Magenta toner containing compound having azo skeleton

ABSTRACT

A toner comprising toner particles, each of which contains a binder resin, a compound in which a polymer portion is bound to an azo skeleton structure, and a magenta pigment.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.13/777,764 filed Feb. 26, 2013, which claims priority to Japanese PatentApplication No. 2012-043073 filed Feb. 29, 2012, each of which arehereby incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magenta toner for use inelectrophotography, electrostatic recording, electrostatic printing, ortoner jet recording, the magenta toner containing a compound having anazo skeleton as a dispersant.

2. Description of the Related Arts

Magenta pigments typically used as colorants for magenta toners aredifficult to disperse due to small pigment particle size. If the pigmentis not sufficiently dispersed in the toner particles, the coloring powerof the toner particles is degraded. This has also led to other problemssuch as significant fluctuation in charging properties due toenvironmental changes such as changes in temperature and humidity and ahigh incidence of “fogging”, that is, development of the toner onbackground portions of images.

Japanese Patent Laid-Open No. 2006-30760 discloses a technique fordispersing a pigment in a toner. According to this technique, aparticular polymer dispersant is used in combination with a magentapigment to enhance the dispersibility of the magenta pigment and improvethe coloring property and charging property of the toner. JapanesePatent Laid-Open No. 11-231572 discloses a method for satisfactorilydispersing a coloring material in a toner by use of a pigment derivativeand a polymer dispersant. Japanese Patent Laid-Open No. 2003-202697discloses a pigment dispersant in which a quinacridone is covalentlybonded to a polymer.

Japanese Patent Laid-Open No. 2-210459 proposes a method that uses adiketopyrrolopyrrole-based pigment instead of a quinacridone pigment inorder to improve the charging stability of the magenta toner andsuppress fogging.

SUMMARY OF THE INVENTION

The polymer dispersant disclosed in Japanese Patent Laid-Open No.2006-30760 generally has poor compatibility with hydrophobic binderresins (such as polystyrene) and has a problem in that the pigment isnot sufficiently dispersed.

The method that uses the pigment derivative and the polymer dispersantdisclosed in Japanese Patent Laid-Open No. 11-231572 results information of a highly polar salt on a pigment surface because thepigment is dispersed by acid-base interaction. Thus, when a toner isproduced in water, the pigment localizes on the toner surfaces andcauses dispersion failure. This results in instable charging, which hasbeen a problem.

The method that uses a dispersant in which a quinacridone is covalentlybonded to a polymer disclosed in Japanese Patent Laid-Open No.2003-202697 needs further improvements since the recent requirements forhigher image quality are not sufficiently met although a certaindispersing effect is exhibited for quinacridone pigments.

According to the method disclosed in Japanese Patent Laid-Open No.2-210459, the dispersibility of the diketopyrrolopyrrole-based pigmentin the toner is still insufficient and fogging on images has not beensatisfactorily prevented.

The present invention provides a magenta toner having high coloringpower in which the dispersibility of a magenta pigment in the binderresin is improved. A magenta toner that suppresses fogging and offershigh transfer efficiency is also provided. A magenta toner comprisingtoner particles, each of which includes a binder resin, a compound and amagenta pigment,

the compound has a structure, a polymer portion of which has a monomerunit represented by formula (2) and is bound to a structure representedby formula (1);

where, in formula (1), at least one of R₂, R₃, Ar₁, and Ar₂ is bound tothe polymer portion directly or through a linking group, wherein each R₁independently represents a hydrogen atom, a halogen atom, an alkylgroup, an alkoxy group, a trifluoromethyl group, a cyano group, or ahydroxyl group; R₂ and R₃ not bound to the polymer portion independentlyrepresent a monovalent group selected from the group consisting of analkyl group, a phenyl group, an OR₄ group, and an NR₅R₆ group; R₄ to R₆independently represent a hydrogen atom, an alkyl group, a phenyl group,or an aralkyl group; Ar₁ and Ar₂ not bound to the polymer portionindependently represent an aryl group; wherein any one of R₂ and R₃bound to the polymer portion independently represents a divalent group,a hydrogen atom of which is removed from the corresponding monovalentgroup of any one of R₂ and R₃;any one of Ar₁ and Ar₂ bound to the polymer portion independentlyrepresents a divalent group, a hydrogen atom of which is removed fromthe corresponding aryl group of any one of Ar₁ and Ar₂; m represents aninteger of 3 or 4; n represents an integer of 1 or 2; and n+m=5,

where, in formula (2), R₇ represents a hydrogen atom or an alkyl group;and R₈ represents a phenyl group, a carboxyl group, a carboxylic acidester group, or a carboxylic acid amide group.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing a ¹H NMR spectrum of a compound (116) havingan azo skeleton in CDCl₃ at room temperature at 400 MHz.

FIG. 2 is a graph showing a ¹H NMR spectrum of a compound (129) havingan azo skeleton in CDCl₃ at room temperature at 400 MHz.

FIG. 3 is a graph showing a ¹H NMR spectrum of a compound (174) havingan azo skeleton in CDCl₃ at room temperature at 400 MHz.

FIG. 4 is a graph showing a ¹H NMR spectrum of a compound (176) havingan azo skeleton in CDCl₃ at room temperature at 400 MHz.

DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described in detail throughembodiments.

A toner according to the present invention comprises toner particles,each of which includes a magenta pigment, a binder resin, and a compoundhaving a structure, a polymer portion of which has a monomer unitrepresented by formula (2) and is bound to a structure represented byformula (1) directly or through a linking group,

[In formula (1), at least one of R₂, R₃, Ar₁, and Ar₂ is bound to thepolymer portion directly or through a linking group, wherein each R₁independently represents a hydrogen atom, a halogen atom, an alkylgroup, an alkoxy group, a trifluoromethyl group, a cyano group, or ahydroxyl group; R₂ and R₃ not bound to the polymer portion independentlyrepresent a monovalent group selected from the group consisting of analkyl group, a phenyl group, an OR₄ group, and an NR₅R₆ group; R₄ to R₆independently represent a hydrogen atom, an alkyl group, a phenyl group,or an aralkyl group; Ar₄ and Ar₂ independently represent an aryl group;wherein any one of R₂ and R₃ bound to the polymer portion independentlyrepresents a divalent group, a hydrogen atom of which is removed fromthe corresponding monovalent group of any one of R₂ and R₃; any one ofAr₄ and Ar₂ bound to the polymer portion independently represents adivalent group, a hydrogen atom of which is removed from thecorresponding aryl group of any one of Ar₁ and Ar₂; m represents aninteger of 3 or 4; n represents an integer of 1 or 2; and n+m=5]

[In formula (2), R₇ represents a hydrogen atom or an alkyl group; and R₈represents a phenyl group, a carboxyl group, a carboxylic acid estergroup, or a carboxylic acid amide group].

The present invention provides a magenta toner that contains, as adispersant, a compound in which a structure represented by formula (1)is linked to a polymer portion having a monomer unit represented byformula (2). This compound has affinity to water-insoluble solvents,polymerizable monomers, and binder resins for toners and high affinityto magenta pigments. Thus, when this compound is used as a pigmentdispersant, the magenta pigment is satisfactorily dispersed in thebinder resin and a magenta toner having high coloring power is provided.Moreover, addition of the compound to the magenta toner suppressesfogging and a magenta toner that offers high transfer efficiency isprovided.

The structure represented by formula (1) may also be referred to as “azoskeleton structure”. The compound in which the azo skeleton structure isbonded to a polymer portion having a monomer unit represented by formula(2) may also be referred to as “compound having an azo skeletonstructure”. The polymer portion having a monomer unit represented byformula (2) not bonded to the azo skeleton structure may be simplyreferred to as “polymer portion”.

The present invention will now be described in detail.

First, the structure of the compound having an azo skeleton structure isdescribed. The compound having an azo skeleton structure is constitutedby an azo skeleton structure represented by formula (1) above havinghigh affinity to magenta pigments and a polymer portion having a monomerunit represented by formula (2) above having high affinity towater-insoluble solvents.

The azo skeleton structure is first described in detail.

Examples of the halogen atom for R₁ in formula (1) above include afluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkyl group for R₁ in formula (1) above include linear,branched, or cyclic alkyl groups such as a methyl group, an ethyl group,an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexylgroup, an isopropyl group, an isobutyl group, a sec-butyl group, atert-butyl group, and a cyclohexyl group.

Examples of the alkoxy group for R₁ in formula (1) include linear orbranched alkoxy groups such as a methoxy group, an ethoxy group, ann-propoxy group, an n-butoxy group, and an isopropoxy group.

R₁ in formula (1) can be freely selected from the above-listedsubstituents, a trifluoromethyl group, a cyano group, a hydroxyl group,and a hydrogen atom but is preferably a hydrogen atom in view ofaffinity to the magenta pigment.

Examples of the substitution positions of the acylacetamide groups informula (1) when m is 4 and n is 1 include cases where the acylacetamidegroups are ortho, meta, or para to each other. The affinity to themagenta pigment is the same irrespective of whether the positions areortho, meta, or para. When m is 3 and n is 2, the acylacetamide groupsmay be substituted in the 1, 2, and 3 positions, 1, 2, and 4 positions,or 1, 3, and 5 positions, for example. The affinity to the magentapigment is also the same irrespective of whether the acylacetamidegroups are substituted in the 1, 2, and 3 positions, 1, 2, and 4positions, or 1, 3, and 5 positions.

Examples of the alkyl group for R₂ and R₃ in formula (1) include linear,branched, or cyclic alkyl groups such as a methyl group, an ethyl group,an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexylgroup, an isopropyl group, an isobutyl group, a sec-butyl group, atert-butyl group, and a cyclohexyl group.

The substituents R₂ and R₃ in formula (1) may be further substitutedwith substituents as long as the affinity to the magenta pigments is notsignificantly degraded. Examples of such substituents include a halogenatom, a nitro group, an amino group, a hydroxyl group, a cyano group,and a trifluoromethyl group.

Examples of the alkyl group for R₄ to R₆ in formula (1) include linear,branched, or cyclic alkyl groups such as a methyl group, an ethyl group,an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexylgroup, an isopropyl group, an isobutyl group, a sec-butyl group, atert-butyl group, and a cyclohexyl group.

Examples of the aralkyl group for R₄ to R₆ in formula (1) include abenzyl group and a phenethyl group.

R₄ to R₆ in formula (1) can be freely selected from the substituentslisted above, a hydrogen atom, and a phenyl group.

Ar₁ and Ar_(e) in formula (1) each represent an aryl group such as aphenyl group or a naphthyl group. These substituents may be furthersubstituted with substituents as long as the affinity to the magentapigment is not significantly degraded. Examples of such substituentsinclude an alkyl group, an alkoxy group, a halogen atom, a hydroxylgroup, a cyano group, a trifluoromethyl group, a carboxyl group, acarboxylic acid ester group, and a carboxylic acid amide group.

At least one of R₂, R₃, Ar₁, and Ar₂ in formula (1) is bound to thepolymer portion directly or through a linking group. At least one of R₂,R₃, Ar₁, and Ar₂ in formula (1) is preferably bound to the polymerportion through a linking group. Any one of R₂ and R₃ bound to thepolymer portion independently represents a divalent group, a hydrogenatom of which is removed from the corresponding monovalent group of anyone of R₂ and R₃. Any one of Ar₁ and Ar₂ bound to the polymer portionindependently represents a divalent group, a hydrogen atom of which isremoved from the corresponding aryl group of any one of Ar₁ and Ar₂. Inview of affinity to the magenta pigment, the structure represented byformula (1) may be a structure represented by formula (3) below. Inother words, in formula (1), Ar₁ and Ar₂ may each represent a phenylgroup, and at least one of hydrogen atoms of the phenyl groups may besubstituted with a linking group to form a link to the polymer portion.

[In formula (3), R₁ is the same as R₁ in formula (1); R₉ and R₁₀independently represent an alkyl group, a phenyl group, an OR₄ group, oran NR₅R₆ group; R₄ to R₆ are the same as R₄ to R₆ in formula (1); R₁₁ toR₂₀ independently represent a linking group or a monovalent groupselected from the group consisting of a hydrogen atom, a COOR₂₁ group, aCONR₂₂R₂₃ group, a NHCOR₂₄ group, and an OR₂₅ group; R₂₁ to R₂₅ eachindependently represent a hydrogen atom, an alkyl group, an aryl group,or an aralkyl group; wherein at least one of R₁₁ to R₂₀ is the linkinggroup that binds to the polymer portion; m represents an integer of 3 or4; n represents an integer of 1 or 2; and n+m=5].

In formula (3), R₁₁ to R₂₀ may each be freely selected from a hydrogenatom, a COOR₂₁ group, a CONR₂₂R₂₃ group, a NHCOR₂₄ group, and an OR₂₅group but preferably at least one of R₁₁ to R₂₀ is a COOR₂₁ group or aCONR₂₂R₂₃ group from the viewpoint of affinity to the magenta pigment.

Examples of the alkyl group for R₂₁ to R₂₅ in formula (3) includelinear, branched, or cyclic alkyl groups such as a methyl group, anethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, ann-hexyl group, an isopropyl group, an isobutyl group, a sec-butyl group,a tert-butyl group, and a cyclohexyl group.

Examples of the aryl group for R₂₁ to R₂₅ in formula (3) include aphenyl group and a naphthyl group.

Examples of the aralkyl group for R₂₁ to R₂₅ in formula (3) include abenzyl group and a phenethyl group.

R₂₁ to R₂₅ in formula (3) may be freely selected from the substituentslisted above and a hydrogen atom. From the viewpoint of the affinity tothe magenta pigment, R₂₁ is preferably a methyl group and R₂₂ and R₂₃are preferably each independently a methyl group or a hydrogen atom.

Examples of the alkyl group for R₉ and R₁₀ in formula (3) includelinear, branched, or cyclic alkyl groups such as a methyl group, anethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, ann-hexyl group, an isopropyl group, an isobutyl group, a sec-butyl group,a tert-butyl group, and a cyclohexyl group.

The substituents R₉ and R₁₀ in formula (3) may be further substitutedwith substituents as long as affinity to the magenta pigment is notsignificantly degraded. Examples of such substituents include a halogenatom, a nitro group, an amino group, a hydroxyl group, a cyano group,and a trifluoromethyl group.

R₉ and R₁₀ in formula (3) can each be freely selected from thesubstituents listed above but are preferably each independently a methylgroup from the viewpoint of affinity to the magenta pigment.

The structure represented by formula (3) is more preferably a structurerepresented by any one of formulae (4) to (7) below from the viewpointof affinity to the magenta pigment. In other words, the azo skeletonstructure portion is preferably bonded to the polymer portion through alinking group L as shown in formulae (4) to (7) below.

[In formula (4), R₁ is the same as R₁ in formula (1); R₉ and R₁₀ are thesame as R₉ and R₁₀ in formula (3); R₂₆ to R₃₀ independently represent ahydrogen atom, a COOR₂₁ group, a CONR₂₂R₂₃ group, a NHCOR₂₄ group, or anOR₂₅ group; R₂₁ to R₂₅ are the same as R₂₁ to R₂₅ in formula (3); 1represents 4; and L represents a divalent linking group that binds tothe polymer portion.]

[In formula (5), R₁ is the same as R₁ in formula (1); R₉ and R₁₀ are thesame as R₉ and R₁₀ in formula (3); R₂₆ to R₃₀ independently represent ahydrogen atom, a COOR₂₁ group, a CONR₂₂R₂₃ group, a NHCOR₂₄ group, or anOR₂₅ group; R₂₁ to R₂₅ are the same as R₂₁ to R₂₅ in formula (3); 1represents 4; and L represents a divalent linking group that binds tothe polymer portion.]

[In formula (6), R₁ is the same as R₁ in formula (1); R₉ is the same asR₉ in formula (3); p represents an integer of 2 or 3; q represents aninteger of 3 or 4; p+q=6; and L represents a divalent linking group thatbinds to the polymer.]

[In formula (7), R₁ is the same as R₁ in formula (1); R₉ is the same asR₉ in formula (3); p represents an integer of 2 or 3; q represents aninteger of 3 or 4; p+q=6; and L represents a divalent linking group thatbinds to the polymer portion.].

L in formulae (4) to (7) above is a divalent linking group and links theazo skeleton structure portion to the polymer portion.

According to the structures represented by formulae (4) and (6), the azoskeleton structure is linked to the polymer portion through L at oneposition. According to the structures of formulae (5) and (7), links areformed at two positions.

L in formulae (4) to (7) may be any divalent linking group butpreferably includes a carboxylic acid ester bond, a carboxylic acidamide bond, or a sulfonic acid ester bond. This is because the reactionthat can induce formation of such bonds is convenient as the reactionfor linking the azo skeleton structure to the polymer portion.

The substitution position of L in formulae (4) to (7) may be that atleast one L is in meta or para position with respect to the hydrazogroup from the viewpoint of the affinity to the magenta pigment.

R₂₆ to R₃₀ in formula (4) or (5) may be selected from a hydrogen atom, aCOOR₂₁ group, a CONR₂₂R₂₃ group, a NHCOR₂₄ group, and an OR₂₅ group.From the viewpoint of affinity to the magenta pigment, at least one ofR₂₆ to R₃₀ is preferably a COOR₂₁ group or a CONR₂₂R₂₃ group.

The polymer portion will now be described in detail.

The alkyl group for R₇ in formula (2) may be any alkyl group. Examplesthereof include linear, branched, or cyclic alkyl groups such as amethyl group, an ethyl group, an n-propyl group, an n-butyl group, ann-pentyl group, an n-hexyl group, an isopropyl group, an isobutyl group,a sec-butyl group, a tert-butyl group, and a cyclohexyl group.

R₇ in formula (2) may be freely selected from the substituents listedabove and a hydrogen atom but is preferably a hydrogen atom or a methylgroup from the viewpoint of polymerizability of the monomer unit.

The carboxylic acid ester group for R₈ in formula (2) may be anycarboxylic acid ester group. Examples thereof include linear or branchedester groups such as a methyl ester group, an ethyl ester group, ann-propyl ester group, an isopropyl ester group, an n-butyl ester group,an isobutyl ester group, a sec-butyl ester group, a tert-butyl estergroup, a dodecyl ester group, a 2-ethylhexyl ester group, a stearylester group, a phenyl ester group, a 2-hydroxyethyl ester group, anoctyl ester group, a nonyl ester group, a decyl ester group, an undecylester group, a dodecyl ester group, a hexadecyl ester group, anoctadecyl ester group, an eicosyl ester group, and a behenyl estergroup.

Examples of the carboxylic acid amide group for R₈ in formula (2)include amide groups such as a N-methylamide group, a N,N-dimethylamidegroup, a N,N-diethylamide group, a N-isopropylamide group, aN-tert-butylamide group, a N-phenylamide group, a N-(2-ethylhexyl)amidegroup, and a N,N-di(2-ethylhexyl)amide group.

The substituent R₈ in formula (2) may be further substituted as long asthe polymerizability of the monomer unit is not impaired and thesolubility of the compound having the azo skeleton structure is notsignificantly degraded. Examples of the substituents include alkoxygroups such as a methoxy group and an ethoxy group, amino groups such asN-methylamino group and a N,N-dimethylamino group, acyl groups such asan acetyl group, and halogen atoms such as a fluorine atom and achlorine atom.

R₈ in formula (2) may be freely selected from the substituents listedabove, a phenyl group, and a carboxyl group but is preferably a phenylgroup or a carboxylic acid ester group from the viewpoints of thedispersibility of the compound having an azo skeleton structure into thebinder resin of the toner and the compatibility between the compound andthe binder resin.

The affinity of the polymer portion to the dispersion medium can becontrolled by changing the content of the monomer unit represented byformula (2). When the dispersion medium is a nonpolar solvent such asstyrene, the content of the monomer unit represented by formula (2) withR₈ representing a phenyl group may be increased from the viewpoint ofaffinity to the dispersion medium. When the dispersion medium is asolvent that has a particular degree of polarity such as an acrylic acidester, the content of the monomer unit represented by formula (2) withR₈ representing a carboxyl group, a carboxylic acid ester group, or acarboxylic acid amide group may be increased from the viewpoint ofaffinity to the dispersion medium.

The number-average molecular weight of the polymer portion may be 500 ormore from the viewpoint of improving the dispersibility of the magentapigment. The larger the molecular weight, the higher the effect ofimproving the dispersibility of the magenta pigment. However, at anexcessively high molecular weight, the affinity to water-insolublesolvents tends to be degraded. Thus, the number-average molecular weightof the polymer portion is preferably up to 200000 and more preferably inthe range of 2000 to 50000 considering the ease of production.

As disclosed in PCT Japanese Translation Patent Publication No.2003-531001, the dispersibility can be improved by using apolyoxyalkylene carbonyl-based dispersant having a branched aliphaticchain introduced at a terminus. If the above-described polymer portioncan be made telechelic by a method such as atom transfer radicalpolymerization (ATRP) described below, a branched aliphatic chain can beintroduced to a terminus and the dispersibility may be improved in somecases.

The substitution positions of the azo skeleton structures in thecompound having the azo skeleton structure may be scattered at random ormay be localized to form one or more blocks at a terminus.

The larger the number of azo skeleton structures substituted in thecompound having the azo skeleton structure, the higher the affinity tothe magenta pigment. However, if the number of the azo skeletonstructures is excessively large, affinity to water-insoluble solvents isdegraded. Thus, the number of the azo skeleton structures is preferablywithin the range of 0.2 to 10 and more preferably within the range of0.2 to 5 per 100 of monomers constituting the polymer portion.

The azo skeleton structure represented by formula (1) has tautomersrepresented by formulae (10) and (11) below as shown below. Thesetautomers are also within the range of the present invention.

[In formulae (10) and (11), R₁ to R₃, Ar₁, Ar₂, m, and n are the same asR₁ to R₃, Ar₁, Ar₂, m, and n in formula (1)].

Examples of the method for synthesizing the compound having an azoskeleton structure include the following methods (i) to (iv).

Method (i): An example scheme of method (i) is described below indetail. First, an azo skeleton structure and a polymer portion areseparately synthesized in advance and then linked to each other bycondensation reaction or the like so as to synthesize a compound havingan azo skeleton structure.

[In formulae (12) to (21), R₁ to R₃, Ar₁, m, and n are the same as R₁ toR₃, Ar₁, m, and n in formula (1); Ar₃ in formulae (20) and (21)represents an arylene group; X₁ in formula (13) and X₂ in formula (18)each represent a leaving group; P₁ represents a polymer portion having amonomer unit represented by general formula (2); X₃ in formulae (20) and(21) represents a substituent that forms the divalent linking group L byreacting with P₁; and r represents an integer of 1 or 2.]

In the scheme described as an example above, the compound having an azoskeleton structure can be synthesized through step 1 of amidating anitroaniline derivative represented by formula (12) and an acetoaceticacid analog represented by formula (13) to synthesize an intermediate(14) which is an acylacetanilide analog; step 2 of performing diazocoupling of the intermediate (14) and an aniline derivative (15) tosynthesize an azo compound (16); step 3 of reducing the nitro groups inthe azo compound (16) to synthesize an intermediate (17) which is ananiline analog; step 4 of amidating the intermediate (17) and anacetoacetic acid analog represented by formula (18) to synthesize anintermediate (19) which is an acylacetanilide analog; step 5 ofperforming diazo coupling of the intermediate (19) and an anilinederivative (20) to synthesize an azo compound (21); and step 6 ofperforming condensation reaction of the azo skeleton and a polymerportion P₁.

First, step 1 is described. A common method may be employed in step 1(e.g., see Datta E. Ponde and four others, The Journal of OrganicChemistry, (USA), American Chemical Society, 1998, vol. 63, No. 4, pp.1058-1063). When R₂ in formula (14) is a methyl group, synthesis ispossible by using a diketone instead of the material (13) (e.g., seeKiran Kumar Solingapuram Sai and two others, The Journal of OrganicChemistry, (USA), American Chemical Society, 2007, vol. 72, No. 25, pp.9761-9764).

There are a wide variety of commercially available products for thenitroaniline derivative (12) and the acetoacetic acid analog (13). Thenitroaniline derivative (12) and the acetoacetic acid analog (13) arealso easy to synthesize by common methods.

This step can be performed in the absence of any solvent but ispreferably performed in the presence of a solvent to suppress rapidprogress of the reaction. The solvent may be any solvent that does notinhibit the reaction and examples thereof include alcohols such asmethanol, ethanol, and propanol, esters such as methyl acetate, ethylacetate, and propyl acetate, ethers such as diethyl ether,tetrahydrofuran, and dioxane, hydrocarbons such as benzene, toluene,xylene, hexane, and heptane, halogen-containing hydrocarbons such asdichloromethane, dichloroethane, and chloroform, amides such asN,N-dimethylformamide, N-methylpyrrolidone, andN,N-dimethylimidazolidinone, nitriles such as acetonitrile andpropionitrile, acids such as formic acid, acetic acid, and propionicacid, and water. Two or more of these solvents may be used as a mixture.In blending the solvents, the blend ratio may be freely determineddepending on the solubility of the substrate. The amount of the solventused may be freely determined but is preferably 1.0 to 20 times theamount of the compound represented by formula (12) on a mass basis fromthe viewpoint of the reaction rate.

This step is usually performed within the temperature range of 0° C. to250° C. and is usually completed within 24 hours.

Next, step 2 is described. In step 2, a common method may be employed.For example, an aniline derivative (15) is reacted with a diazotizingagent such as sodium nitrite or nitrosylsulfuric acid in a methanolsolvent in the presence of an inorganic acid such as hydrochloric acidor sulfuric acid so as to synthesize a corresponding a diazonium salt.This diazonium salt is coupled with the intermediate (14) to synthesizethe azo compound (16).

There are a wide variety of commercially available products for theaniline derivative (15). The aniline derivative (15) is also easy tosynthesize by common methods.

This step can be performed in the absence of any solvent but ispreferably conducted in the presence of a solvent to suppress rapidprogress of the reaction. The solvent may be any solvent that does notinhibit the reaction. Examples thereof include alcohols such asmethanol, ethanol, and propanol, esters such as methyl acetate, ethylacetate, and propyl acetate, ethers such as diethyl ether,tetrahydrofuran, and dioxane, hydrocarbons such as benzene, toluene,xylene, hexane, and heptane, halogen-containing hydrocarbons such asdichloromethane, dichloroethane, and chloroform, amides such asN,N-dimethylformamide, N-methylpyrrolidone, andN,N-dimethylimidazolidinone, nitriles such as acetonitrile andpropionitrile, acids such as formic acid, acetic acid, and propionicacid, and water. Two or more of these solvents may be used as a mixture.In blending the solvents, the blend ratio may be freely determineddepending on the solubility of the substrate. The amount of the solventused may be freely determined but is preferably 1.0 to 20 times theamount of the compound represented by formula (15) on a mass basis fromthe viewpoint of the reaction rate.

This step is usually performed within the temperature range of −50° C.to 100° C. and is usually completed within 24 hours.

Step 3 will now be described. In step 3, a common method may be employed(an example of a method that uses a metal compound and the like isdescribed in “Jikken Kagaku Kouza [Experimental Chemistry]”, publishedby Maruzen Publishing Co., Ltd., first edition, vol. 17-2, pp. 162-179and an example of a catalytic hydrogenation method is described in“Jikken Kagaku Kouza [Experimental Chemistry]”, published by MaruzenPublishing Co., Ltd., first edition, vol. 15, pp. 390-448 orInternational Publication No. 2009/060886 pamphlet).

This step can be performed in the absence of any solvent but ispreferably performed in the presence of a solvent to suppress rapidprogress of the reaction. The solvent may be any solvent that does notinhibit the reaction and examples thereof include alcohols such asmethanol, ethanol, and propanol, esters such as methyl acetate, ethylacetate, and propyl acetate, ethers such as diethyl ether,tetrahydrofuran, and dioxane, hydrocarbons such as benzene, toluene,xylene, hexane, and heptane, and amides such as N,N-dimethylformamide,N-methylpyrrolidone, and N,N-dimethylimidazolidinone. Two or more ofthese solvents may be used as a mixture. In blending the solvents, theblend ratio may be freely determined. The amount of the solvent used maybe freely determined depending on the solubility of the substrate but ispreferably 1.0 to 20 times the amount of the compound represented byformula (16) on a mass basis from the viewpoint of the reaction rate.

This step is usually performed within the temperature range of 0° C. to250° C. and is usually completed within 24 hours.

Next, step 4 is described. In step 4, the same method as in step 1 isemployed to synthesize the intermediate (19) which is an acylacetanilideanalog.

Next, step 5 is described. In step 5, the same method as in step 2 isemployed to synthesize the azo compound (21).

There are a wide variety of commercially available products for theaniline derivative (20). The aniline derivative (20) is also easy tosynthesize by common methods.

Next, a method for synthesizing the polymer portion P₁ used in step 6 isdescribed. A common polymerization method may be employed insynthesizing the polymer portion P₁ (e.g., see Krzysztof Matyjaszewskiand one other, Chemical Reviews, (USA), American Chemical Society, 2001,vol. 101, pp. 2921-2990).

Specific examples thereof include radical polymerization, cationicpolymerization, and anionic polymerization. Preferably, radicalpolymerization is employed due to ease of production.

Radical polymerization may be conducted by using a radicalpolymerization initiator, by applying radiation, a laser beam, or thelike, by using a photopolymerization initiator and applying light, or byheating, for example.

The radical polymerization initiator may be any that can generate aradical and initiate polymerization reaction and may be selected fromamong the compounds that generate radicals due to heat, light,radiation, redox reaction, and the like. Examples thereof include azocompounds, organic peroxides, inorganic peroxides, organic metalcompounds, and photopolymerization initiators. Specific examples thereofinclude azo-based polymerization initiators such as2,2′-azobis(isobutyronitrile), 2,2′-azobis(2-methylbutyronitrile),2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), and2,2′-azobis(2,4-dimethylvaleronitrile), organic peroxide-basedpolymerization initiators such as benzoyl peroxide, di-tert-butylperoxide, tert-butylperoxyisopropyl carbonate, tert-hexylperoxybenzoate, and tert-butylperoxy benzoate, inorganic peroxide-basedpolymerization initiators such as potassium persulfate and ammoniumpersulfate, and redox initiators such as those based on hydrogenperoxide-ferrous iron, benzoyl peroxide-dimethylaniline, and cerium(IV)salt-alcohol. Examples of the photopolymerization initiator includebenzophenones, benzoin ethers, acetophenones, and thioxanthones. Two ormore of these radical polymerization initiators may be used incombination.

The amount of the polymerization initiator used may be adjusted withinthe range of 0.1 to 20 parts by mass per 100 parts by mass of themonomers so that a copolymer having a desired molecular weightdistribution is obtained.

The polymer portion represented by P₁ can be prepared by any method suchas solution polymerization, suspension polymerization, emulsionpolymerization, dispersion polymerization, precipitation polymerization,and bulk polymerization. Solution polymerization in a solvent that candissolve all the components used in production is preferred. Examples ofthe solvent that can be used include polar organic solvents such asalcohols, e.g., methanol, ethanol, and 2-propanol, ketones, e.g.,acetone and methyl ethyl ketone, ethers, e.g., tetrahydrofuran anddiethyl ether, ethylene glycol monoalkyl ethers or acetates thereof,propylene glycol monoalkyl ethers or acetates thereof, and diethyleneglycol monoalkyl ethers; and, if appropriate, nonpolar solvents such astoluene and xylene. These solvents can be used alone or in combination.Preferably, solvents having a boiling point within the range of 100° C.to 180° C. are used alone or in combination among these solvents.

The polymerization temperature is not particularly limited since apreferable temperature range differs depending on types of initiatorsused. The temperature range for polymerization is usually −30° C. to200° C. and is preferably 40° C. to 180° C.

The molecular weight distribution and molecular structure of the polymerportion represented by P₁ can be controlled by common methods. Examplesof such methods include a method in which an addition fragmentation typechain transfer agent is used (refer to Japanese Patent Nos. 4254292 and3721617), a nitroxide-mediated polymerization (NMP) method in whichdissociation and bonding of amine oxide radicals are utilized [see CraigJ. Hawker and two others, Chemical Reviews, (USA), American ChemicalSociety, 2001, vol. 101, pp. 3661-3688], an atom transfer radialpolymerization (ATRP) method in which polymerization is conducted byusing a metal catalyst, a ligand, and a halogen compound as apolymerization initiator [see Masami Kamigaito and two others, ChemicalReviews, (USA), American Chemical Society, 2001, vol. 101, pp.3689-3746], a reversible addition fragmentation chain transfer (RAFT)method that uses a dithiocarboxylic acid ester, a xanthate compound, orthe like as a polymerization initiator (e.g., PCT Japanese TranslationPatent Publication No. 2000-515181), a MADIX (macromolecular design viainterchange of xanthates) method (e.g., see International PublicationNo. 99/05099 pamphlet), and a degenerative transfer (DT) method [forexample, see Atsushi Goto and six others, Journal of The AmericanChemical Society, (USA), American Chemical Society, 2003, vol. 125, pp.8720-8721]. A polymer portion P₁ with controlled molecular weightdistribution and molecular structure can be produced by these methods.

Next, step 6 is described. In step 6, a common method may be employed.For example, a polymer portion P₁ having a carboxyl group and an azocompound (21) with X₃ representing a substituent having a hydroxyl groupmay be used to synthesize a compound having an azo skeleton structurewith a linking group L having a carboxylic acid ester bond.Alternatively, a polymer portion P₁ having a hydroxyl group and an azocompound (21) with X₃ representing a substituent having a sulfonic acidgroup may be used to synthesize a compound having an azo skeletonstructure with a linking group L having a sulfonic acid ester bond. Yetalternatively, a polymer portion P₁ having a carboxyl group and an azocompound (21) with X₃ representing a substituent having an amino groupmay be used to synthesize a compound having an azo skeleton structurewith a linking group L having a carboxylic acid amide bond. Specificexamples of such methods include a method that uses a dehydrationcondensation agent, e.g., 1-ethyl-3-(3-dimethylaminopropyl) carbodiimidehydrochloride (for example, see Melvin S. Newman and one other, TheJournal of Organic Chemistry, (USA), American Chemical Society, 1961,vol. 26, No. 7, pp. 2525-2528) and a Schotten-Baumann method (forexample, see Norman O. V. Sonntag, Chemical Reviews, (USA), AmericanChemical Society, 1953, vol. 52, No. 2, pp. 237-416).

This step can be performed in the absence of any solvent but ispreferably performed in the presence of a solvent to suppress rapidprogress of the reaction. The solvent may be any solvent that does notinhibit the reaction and examples thereof include ethers such as diethylether, tetrahydrofuran, and dioxane, hydrocarbons such as benzene,toluene, xylene, hexane, and heptane, halogen-containing hydrocarbonssuch as dichloromethane, dichloroethane, and chloroform, amides such asN,N-dimethylformamide, N-methylpyrrolidone, andN,N-dimethylimidazolidinone, and nitriles such as acetonitrile andpropionitrile. Two or more of these solvents may be used as a mixturedepending on the solubility of the substrate. In blending the solvents,the blend ratio may be freely determined. The amount of the solvent usedmay be freely determined but is preferably 1.0 to 20 times the amount ofthe compound represented by formula (21) on a mass basis from theviewpoint of the reaction rate.

This step is usually performed within the temperature range of 0° C. to250° C. and is usually completed within 24 hours.

Next, method (ii) is described in detail by using an example schemebelow. In method (ii), an azo compound having a polymerizable functionalgroup is prepared in advance and then copolymerized with a polymerizablemonomer that forms a monomer unit represented by formula (2) to therebysynthesize the compound having an azo skeleton structure.

[In formula (21), R₁ to R₃, Ar₁, Ar₃, X₃, m, n, and r are the same as R₁to R₃, Ar₁, Ar₃, X₃, m, n, and r in formula (21) in the scheme of method(i) above; R₄₅ in formula (22) represents a hydrogen atom or an alkylgroup; X₄ represents a substituent that reacts with X₃ in formula (21)to give X₅ in formula (23); R₁ to R₃, R₄₅, Ar₁, Ar₃, m, n, and r informula (23) are the same as those in formulae (21) and (22); and X₅represents a divalent linking group L formed by reaction between X₃ informula (21) and X₄ in formula (22).]

In the scheme illustrated above, a compound having an azo skeletonstructure is synthesized through step 7 of reacting an azo compound (21)with a vinyl group containing compound represented by formula (22) tosynthesize an azo compound (23) having a polymerizable functional groupand step 8 of copolymerizing the azo compound (23) having apolymerizable functional group and a polymerizable monomer that formsthe monomer unit represented by formula (2).

First, step 7 is described. In step 7, the same method as in step 6 ofmethod (i) above is employed to synthesize an azo compound (23) having apolymerizable functional group.

There are a wide variety of commercially available products for thevinyl group containing compound (22). The vinyl group containingcompound (22) is also easy to synthesize by common methods.

Next, step 8 is described. In step 8, the method for synthesizing thepolymer portion P₁ in method (i) can be used to synthesize a compoundhaving an azo skeleton structure through copolymerization of the azocompound (23) having a polymerizable functional group and thepolymerizable monomer that forms the monomer unit represented by formula(2).

Next, method (ii) is described in detail by using an example schemebelow. In method (iii), an azo compound having a halogen atomsynthesized in advance is used as a polymerization initiator andcopolymerized with a polymerizable monomer that forms the monomer unitrepresented by formula (2) so as to synthesize a compound having the azoskeleton structure.

[In formula (21), R₁ to R₃, Ar₁, Ar₃, X₃, m, n, and r are the same as R₁to R₃, Ar₁, Ar₃, X₃, m, n, and r in formula (21) in method (i) above; X₆in formula (24) represents a substituent that reacts with X₃ in formula(21) to give X₇ in formula (25); A represents a chlorine atom, a bromineatom, or an iodine atom; R₁ to R₃, Ar₁, Ar₂, X₃, m, n and r in formula(25) are the same as those in formula (21); and X₇ represents a divalentlinking group L formed by reaction between X₃ in formula (21) and X₆ informula (24).]

In the scheme illustrated above, a compound having an azo skeletonstructure is synthesized through step 9 of reacting an azo compound (21)with a halogen atom-containing compound represented by formula (24) tosynthesize an azo compound (25) having a halogen atom and step 10 ofpolymerizing the halogen atom-containing azo compound (25) serving as apolymerizing initiator with a polymerizable monomer that forms themonomer unit represented by formula (2).

First, step 9 is described. In step 9, the same method as in step 6 ofmethod (i) above is employed to synthesize a halogen atom-containing azocompound (25). For example, a halogen atom-containing azo skeletonstructure (25) having a linking group L containing a carboxylic acidester bond can be synthesized by using a halogen atom-containingcompound (24) having a carboxyl group and an azo compound (21) with X₃representing a substituent having a hydroxyl group. Alternatively, ahalogen atom-containing azo skeleton structure (25) having a linkinggroup L containing a sulfonic acid ester bond can be synthesized byusing a halogen atom-containing compound (24) having a hydroxyl groupand an azo compound (21) with X₃ representing a substituent having asulfonic acid group. Yet alternatively, a halogen atom-containing azoskeleton structure (25) having a linking group L containing a carboxylicacid amide bond can be synthesized by using a halogen atom-containingcompound (24) having a carboxyl group and an azo compound (21) with X₃representing a substituent having an amino group.

Examples of the halogen atom-containing compound (24) having a carboxylgroup include chloroacetic acid, α-chloropropionic acid, α-chlorobutyricacid, α-chloroisobutyric acid, α-chlorovaleric acid, α-chloroisovalericacid, α-chlorocaproic acid, α-chlorophenylacetic acid,α-chlorodiphenylacetic acid, α-chloro-α-phenylpropionic acid,α-chloro-β-phenylpropionic acid, bromoacetic acid, α-bromopropionicacid, α-bromobutyric acid, α-bromoisobutyric acid, α-bromovaleric acid,α-bromoisovaleric acid, α-bromocaproic acid, α-bromophenylacetic acid,α-bromodiphenylacetic acid, α-bromo-α-phenylpropionic acid,α-bromo-β-phenylpropionic acid, iodoacetic acid, α-iodopropionic acid,α-iodobutyric acid, α-iodoisobutyric acid, α-iodovaleric acid,α-iodoisovaleric acid, α-iodocaproic acid, α-iodophenylacetic acid,α-iododiphenylacetic acid, α-iodo-α-phenylpropionic acid,α-iodo-β-phenylpropionic acid, β-chlorobutyric acid, β-bromoisobutyricacid, iododimethylmethylbenzoic acid, and 1-chloroethylbenzoic acid.Acid halides and acid anhydrides thereof can also be used in the presentinvention.

Examples of the halogen atom-containing compound (24) having a hydroxylgroup include 1-chloroethanol, 1-bromoethanol, 1-iodoethanol,1-chloropropanol, 2-bromopropanol, 2-chloro-2-propanol,2-bromo-2-methylpropanol, 2-phenyl-1-bromoethanol, and2-phenyl-2-iodoethanol.

Next, step 10 is described. In step 10, the ATRP method described inmethod (i) above is used to synthesize a compound having an azo skeletonstructure by polymerizing a halogen atom-containing azo skeletonstructure (25) serving as a polymerization initiator with apolymerizable monomer that forms the monomer unit represented by formula(2) in the presence of a metal catalyst and a ligand.

The metal catalyst used in the ATRP method is not particularly limitedbut may be at least one transition metal selected from groups 7 to 11 inthe periodic table. For a redox catalyst (redox conjugated complex) inwhich a low valence complex and a high valence complex changereversibly, the low valence metal specifically used is, for example, ametal selected from the group consisting of Cu⁺, Ni⁰, Ni⁺, Ni²⁺, Pd⁰,Pd⁺, Pt⁰, Pt⁺, Pt²⁺, Rh⁺, Rh²⁺, Rh³⁺, Co⁺, Co²⁺, Ir⁰, Ir⁺, Ir²⁺, Ir³⁺,Fe²⁺, Ru²⁺, Ru³⁺, Ru⁴⁺, Ru⁵⁺, Os²⁺, Os³⁺, Re²⁺, Re³⁺, Re⁴⁺, Re⁶⁺, Mn²⁺,and Mn³⁺. Among these, Cu⁺, Ru²⁺, Fe²⁺, or Ni²⁺ is preferred and Cu⁺ isparticularly preferable due to its high availability. The monovalentcopper compound may be cuprous chloride, cuprous bromide, cuprousiodide, or cuprous cyanide.

The ligand used in the ATRP method is typically an organic ligand.Examples thereof include 2,2′-bipyridyl and derivatives thereof,1,10-phenanthroline and derivatives thereof,N,N,N′,N′-tetramethylethylenediamine,N,N,N′,N″,N″-pentamethyldiethylenetriamine,tris[2-(dimethylamino)ethyl]amine, triphenylphosphine, andtributylphosphine. Considering the ease of production, aliphaticpolyamines such as N,N,N′,N″,N″-pentamethyldiethylenetriamine may beused.

Next, method (iv) is described in detail by using an example schemebelow. In method (iv), a polymer portion having a monomer unitrepresented by formula (2) bonded to an amino group-containing arylgroup and an intermediate which is an acylacetanilide analog areseparately synthesized in advance and then subjected to diazo couplingso as to form a compound having an azo skeleton structure.

[P₁ is the same as P₁ in the scheme of method (i) above; R₁ to R₃, Ar₁,m, and n in formula (19) are the same as R₁ to R₃, Ar₁, m, and n informula (19) of the scheme of method (i); Ar₄ in formulae (26) to (28)represents an arylene group; X₈ in formula (26) represents a substituentthat reacts with P₁ to give X₉ in formula (27); r represents 1 or 2; andX₉ in formulae (27) and (28) represents a divalent linking group Lformed by the reaction between X₈ in formula (26) and P₁.]

In the scheme illustrated above, a compound having an azo skeletonstructure is synthesized through step 11 of introducing a nitrogroup-containing arylene group (26) into the polymer portion P₁ tosynthesize a polymer portion (27) having a nitro group-containingarylene group, step 12 of reducing the polymer portion (27) having anitro group-containing arylene group to synthesize a polymer portion(28) having an amino group-containing arylene group, and step 13 ofperforming diazo coupling of the polymer portion (28) having an aminogroup-containing arylene group and an intermediate (19) which is anacylacetanilide analog.

First, step 11 is described. In step 11, the same method as in step 6 ofmethod (i) above is employed to synthesize a polymer portion (27) havinga nitro group-containing arylene group. For example, a polymer portion(27) having a nitro group-containing arylene group with a carboxylicacid ester bond serving as a linking group can be synthesized byreacting a polymer portion P₁ having a carboxyl group with a nitrogroup-containing arylene group (26) with X₈ representing a hydroxylgroup-containing substituent. A polymer portion (27) having a nitrogroup-containing arylene group with a sulfonic acid ester bond servingas a linking group can be synthesized by reacting a polymer portion P₁having a hydroxyl group with a nitro group-containing arylene group (26)with X₈ representing a substituent containing a sulfonic acid. A polymerportion (27) having a nitro group-containing arylene group with acarboxylic acid amide bond serving as a linking group can be synthesizedby reacting a polymer portion P₁ having a carboxyl group with a nitrogroup-containing arylene group (26) with X₈ representing a substituentcontaining an amino group.

There are a wide variety of commercially available products for thenitro group-containing arylene group (26). The nitro group-containingarylene group (26) is also easy to synthesize by common methods.

Next, step 12 is described. In step 12, the same method as step 3 inmethod (i) above is applied to synthesize a polymer portion (28) havingan amino group-containing arylene group.

Next, step 13 is described. In step 13, the same method as step 2 inmethod (i) above is applied to synthesize a compound having an azoskeleton structure.

The compounds having an azo skeleton structure obtained in the steps ofthe synthetic methods illustrated above and the compounds represented byformulae (14), (16), (17), (19), (21), (23), (25), (27), and (28) can bepurified through a typical isolation or purifying method for organiccompounds. Examples of the isolation or purifying method include arecrystallization method and a reprecipitation method that use organicsolvents, and column chromatography using silica gel and the like. Oneor a combination of two or more of these methods may be used to purifythe compounds and obtain high-purity compounds.

The compounds represented by formulae (14), (16), (17), (19), (21),(23), and (25) obtained in the steps of the synthetic methodsillustrated above were identified and analyzed to determine the purityby nuclear magnetic resonance spectroscopy (ECA-400 produced by JEOLLtd.), ESI-TOF MS (LC/MSD TOF produced by Agilent Technologies), andHPLC analysis (LC-20A produced by Shimadzu Corporation).

The compounds having an azo skeleton structure obtained by the syntheticmethods illustrated above and the polymer portions represented byformulae (27) and (28) were identified and analyzed to determine themolecular weight by size exclusion chromatography (SEC) (HLC8220GPCproduced by Tosoh Corporation), nuclear magnetic resonance spectroscopy(ECA-400 produced by JEOL Ltd.), and acid value measurement according toJapanese Industrial Standard (JIS) K-0070 (automatic titrator COM-2500produced by Hiranuma Sangyo Corporation).

Next, the binder resin of the toner of the present invention isdescribed.

Examples of the binder resin of the toner of the present inventioninclude commonly used binder resins such as styrene-methacrylic acidcopolymers, styrene-acrylic acid copolymers, polyester resins, epoxyresins, and styrene-butadiene copolymers. In a method of directlyobtaining toner particles by polymerization, monomers that form thebinder resin are used. Examples thereof include styrene-based monomerssuch as styrene, α-methylstyrene, α-ethylstyrene, o-methylstyrene,m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, andp-ethylstyrene; methacrylate-based monomers such as methyl methacrylate,ethyl methacrylate, propyl methacrylate, butyl methacrylate, octylmethacrylate, dodecyl methacrylate, stearyl methacrylate, behenylmethacrylate, 2-ethylhexyl methacrylate, dimethylaminoethylmethacrylate, diethylaminoethyl methacrylate, methacrylonitrile, andamide methacrylate; acrylate-based monomers such as methyl acrylate,ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, dodecylacrylate, stearyl acrylate, behenyl acrylate, 2-ethylhexyl acrylate,dimethylaminoethyl acrylate, diethylaminoethyl acrylate, acrylonitrile,and amide acrylate; and olefin-based monomers such as butadiene,isoprene, and cyclohexene. These are used alone or as a mixture of twoor more so that the theoretical glass transition temperature (Tg)thereof is within the range of 40° C. to 75° C. (refer to J. Brandrup,E. H. Immergut (editor), Polymer Handbook, (USA), third edition, JohnWiley & Sons, 1989, pp. 209-277). When the theoretic glass transitiontemperature is less than 40° C., the storage stability and durabilitystability of the toner may be degraded. When the theoretic glasstransition temperature exceeds 75° C., transparency is degraded when thetoner is used to form full color images.

The binder resin of the toner of the present invention may beconstituted by a nonpolar resin such as polystyrene and a polar resinsuch as a polyester resin or a polycarbonate resin so that the in-tonerdistribution of additives such as a colorant, a charge controller, and awax can be controlled. For example, in the case where toner particlesare directly produced by suspension polymerization or the like, thepolar resin is added during a polymerization reaction performed in thedispersing step through the polymerization step. The polar resin isadded depending on the balance of polarity between a water-based mediumand the polymerizable monomer composition that forms toner particles. Inthis manner, the resin concentration can be controlled to continuouslychange from the toner particle surface toward the toner particle center,because, for example, a thin layer of the polar resin can be formed onthe surfaces of toner particles. The polar resin used here may be apolar resin that can interact with the compound having an azo skeletonstructure, a colorant, and a charge controller so that the state ofpresence of the colorant in the toner particles can be controlled asdesired.

Examples of the magenta pigments that can be used in the toner of thepresent invention include magenta pigments (for example,quinacridone-based pigments, monoazonaphthol-based pigments,disazonaphthol-based pigments, perylene-based pigments, thioindigo-basedpigments, and diketopyrrolopyrrole-based pigments) described in OrganicPigments Handbook published in 2006 (written by Isao Hashimoto) and themagenta pigment may be appropriately selected from these. In particular,quinacridone-based pigments and diketopyrrolopyrrole-based pigments arepreferred since they have high affinity to the pigment dispersant of thepresent invention and offer magenta toners with high coloringproperties.

Quinacridone-based pigments and diketopyrrolopyrrole-based pigments foruse as a colorant of the toner of the present invention are preferablyrepresented by formulae (8) and (9) below from the viewpoint of affinityto the pigment dispersant of the present invention:

[In formula (8), R₃₁ to R₃₈ independently represent a hydrogen atom, achlorine atom, or a methyl group.]

[In formula (9), R₃₉ to R₄₄ independently represent a hydrogen atom, achlorine atom, a tert-butyl group, a cyano group, or a phenyl group.]

In formula (8), R₃₁ to R₃₈ may each be freely selected from thesubstituents listed above. From the viewpoint of coloring power, R₃₁ toR₃₂, R₃₄ to R₃₆, and R₃₈ each preferably represent a hydrogen atom. Morepreferably, R₃₃ and R₃₇ each represent a hydrogen atom, a chlorine atomor a methyl group.

In formula (9), R₃₉ to R₄₄ may each be freely selected from thesubstituents listed above. From the viewpoint of coloring power, R₃₉,R₄₁ and R₄₂, and R₄₄ each preferably represent a hydrogen atom. Morepreferably, R₄₀ and R₄₃ each represent a hydrogen atom or a phenylgroup.

Specific examples of the quinacridone-based pigments represented byformula (8) include C.I. Pigment Red 202, C.I. Pigment Red 122, C.I.Pigment Red 192, and C.I. Pigment Red 209. Specific examples ofdiketopyrrolopyrrole-based pigments represented by formula (9) includeC.I. Pigment Red 255, C.I. Pigment Red 254, and C.I. Pigment Red 264.

In order to obtain a magenta toner having higher coloring power, themagenta pigment used in combination with the compound having an azoskeleton structure of the present invention is preferably C.I. PigmentRed 122, C.I. Pigment Red 202, C.I. Pigment Red 255, or C.I. Pigment Red264.

These magenta pigments may be used alone or in combination.

The ratio of the content of the magenta pigment to the content of thecompound having an azo skeleton structure on a mass basis is preferablyin the range of 100:0.1 to 100:100. More preferably, when the specificsurface area of the magenta pigment is 300 m²/g or less, this ratio isin the range of 100:0.5 to 100:20 from the viewpoint to dispersibilityof the magenta toner.

One or more of the magenta pigments need to be used as the colorant ofthe toner of the present invention but other colorants may additionallybe used as long as the dispersibility of the magenta pigment is notinhibited.

Examples of such colorants that can be additionally used include commonmagenta colorants.

Examples of the magenta colorant that can be additionally used includefused azo compounds, anthraquinone, basic dye lake compounds, naphtholcompounds, benzimidazolone compounds, thioindigo compounds, and perylenecompounds. Specific examples thereof include C.I. Pigment Red 2, C.I.Pigment Red 3, C.I. Pigment Red 5, C.I. Pigment Red 6, C.I. Pigment Red7, C.I. Pigment Red 23, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3,C.I. Pigment Red 48:4, C.I. Pigment Red 57:1, C.I. Pigment Red 81:1,C.I. Pigment Red 144, C.I. Pigment Red 146, C.I. Pigment Red 150, C.I.Pigment Red 166, C.I. Pigment Red 169, C.I. Pigment Red 177, C.I.Pigment Red 184, C.I. Pigment Red 185, C.I. Pigment Red 220, C.I.Pigment Red 221, C.I. Pigment Red 238, and C.I. Pigment Red 269.

The amount of these colorants used differs depending on the type of thecolorants. The total colorant content is 0.1 to 60 parts by mass andmore preferably 0.5 to 50 parts by mass relative to 100 parts by mass ofthe binder resin.

During the synthesis of the binder resin, a crosslinking agent may beused to enhance the mechanical strength of the toner particles andcontrol the molecular weight of the molecules constituting theparticles.

Examples of the crosslinking agent used in toner particles of thepresent invention include difunctional crosslinking agents. Examples ofthe difunctional crosslinking agents include divinylbenzene,bis(4-acryloxypolyethoxyphenyl)propane, ethylene glycol diacrylate,1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate,1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycoldiacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,tetraethylene glycol diacrylate, diacrylates of polyethylene glycol#200, #400, and #600, dipropylene glycol diacrylate, polypropyleneglycol diacrylate, polyester-type diacrylate, and dimethacrylates ofthese diacrylates.

Examples of the multifunctional crosslinking agent includepentaerythritol triacrylate, trimethylolethane triacrylate,trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate,oligo ester acrylate, and methacrylates thereof,2,2-bis(4-methacryloxyphenyl)propane, diallyl phthalate, triallylcyanurate, triallyl isocyanurate, and triallyl trimellitate.

These crosslinking agents are preferably used in an amount in the rangeof 0.05 to 10 parts by mass and more preferably in an amount in therange of 0.1 to 5 parts by mass relative to 100 parts by mass of themonomer from the viewpoints of fixability of the toner and offsetresistance.

A wax component may also be used during synthesis of the binder resin inorder to prevent adhesion of the toner to the fixing member.

Examples of the wax component that can be used include petroleum waxessuch as paraffin wax, microcrystalline wax, and petrolatum andderivatives thereof, montan wax and derivatives thereof, hydrocarbon waxproduced by Fischer-Tropsch processes and derivatives thereof,polyolefin wax such as polyethylene and derivatives thereof, and naturalwax such as carnauba wax and candelilla wax and derivatives thereof.Derivatives may refer to oxides, block copolymers with vinyl monomers,and graft modified products. Further examples thereof include alcoholssuch as higher aliphatic alcohols, fatty acids such as stearic acid andpalmitic acid, fatty acid amides, fatty acid esters, hydrogenated castoroil and derivatives thereof, vegetable wax, and animal wax. These may beused alone or in combination.

The total amount of the wax component added is preferably within therange of 2.5 to 15.0 parts by mass and more preferably within the rangeof 3.0 to 10.0 parts by mass relative to 100 parts by mass of the binderresin. If the amount of wax is smaller than 2.5 parts by mass, oil-lessfixing becomes difficult. When the amount exceeds 15.0 parts by mass,the amount of the wax component in the toner particles becomesexcessively large, and large quantities of excess wax component may bepresent on the toner particles surfaces, possibly adversely affectingcharging properties.

A charge controller can be blended to the toner of the present inventionas needed. The optimum triboelectric charge amount for the developmentsystem can be controlled with the charge controller.

Any common charge controller may be used. A charge controller that hashigh charging speed and is capable of stably retaining a particularamount of charge is preferred. In the case where toner particles areformed directly by polymerization, a charge controller that rarelyinhibits polymerization and that is substantially free of matter solublein water-based dispersion media is particularly preferable.

Examples of the charge controller that negatively charges the tonerinclude polymers or copolymers having a sulfonic acid group, a sulfonicacid base, or a sulfonic acid ester group, salicylic acid derivativesand metal complexes thereof, monoazo metal compounds, acetylacetonemetal compounds, aromatic oxycarboxylic acids, aromatic mono- orpolycarboxylic acids and metal salts, anhydrides, and esters thereof,phenol derivatives such as bisphenol, urea derivatives, metal-containingnaphthoic acid-based compounds, boron compounds, quaternary ammoniumsalts, calixarene, and resin-based charge controllers. Examples of thecharge controller that positively charges the toner include nigrosin andnigrosin products modified with fatty acid metal salts or the like,guanidine compounds, imidazole compounds,tributylbenzylammonium-1-hydroxy-4-naphtholsulfonic acid salts,quaternary ammonium salts such as tetrabutylammonium tetrafluoroborate,onium salts such as phosphonium salts of analogs of the foregoing andlake pigments thereof, triphenyl methane dyes and lake pigments thereof(examples of the laking agent include phosphotungstic acid,phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauricacid, gallic acid, ferricyanide, and ferrocyanide), metal salts ofhigher fatty acids, diorganotin oxides such as dibutyltin oxide,dioctyltin oxide, and dicyclohexyltin oxide, diorganotin borates such asdibutyltin borate and dioctyltin borate, and resin-based chargecontrollers. These may be used alone or in combination.

An inorganic fine powder serving as a flowing agent may be added to thetoner particles of the toner of the present invention. Examples of theinorganic fine powder include silica, titanium oxide, alumina, a complexoxide thereof, and a surface-treated fine powder thereof.

Examples of the method for producing toner particles constituting thetoner of the present invention include a grinding method, a suspensionpolymerization method, a suspension granulation method, and an emulsionpolymerization method. From the viewpoints of environmental load duringproduction and controllability of particle size, a production methodwith which particles are formed in water-based media, such as asuspension polymerization method or a suspension granulation method, ispreferred.

In the method for producing toner of the present invention, a compoundhaving an azo skeleton structure and a magenta pigment may be mixed inadvance to prepare a pigment composition. In this manner, thedispersibility of the magenta pigment can be improved.

The pigment composition can be produced by a dry process or a wetprocess. Considering that the compound having an azo skeleton structurehas high affinity to water-insoluble solvents, a wet process ispreferred since a homogeneous pigment composition can be easilyproduced. An example of such a method is as follows. A compound havingan azo skeleton structure and, if needed, a resin are added to adispersion medium. A magenta pigment powder is slowly added to themixture under stirring so that the magenta pigment powder is thoroughlymixed with the dispersion medium. Then mechanical shear force is appliedto the resulting mixture with a disperser such as a kneader, a rollmill, a ball mill, a paint shaker, a dissolver, an attritor, a sandmill, or a high-speed mill. As a result, the magenta pigment can bestably and uniformly dispersed into fine particles.

The dispersion medium that can be used in the pigment composition may beany. In order for the compound having an azo skeleton structure toachieve high pigment dispersing effect, the dispersion medium ispreferably a water-insoluble solvent. Examples of the water-insolublesolvent include esters such as methyl acetate, ethyl acetate, and propylacetate, hydrocarbons such as hexane, octane, petroleum ethers,cyclohexane, benzene, toluene, and xylene, and halogen-containinghydrocarbon such as carbon tetrachloride, trichloroethylene, andtetrabromoethane.

The dispersion medium that can be used in the pigment composition may bea polymerizable monomer. Examples thereof include styrene,α-methylstyrene, α-ethylstyrene, o-methylstyrene, m-methylstyrene,p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene,3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene,p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene,p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene,p-n-dodecylstyrene, ethylene, propylene, butylene, isobutylene, vinylchloride, vinylidene chloride, vinyl bromide, vinyl iodide, vinylacetate, vinyl propionate, vinyl benzoate, methacrylic acid, methylmethacrylate, ethyl methacrylate, propyl methacrylate, butylmethacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexylmethacrylate, stearyl methacrylate, behenyl methacrylate, phenylmethacrylate, dimethylaminoethyl methacrylate, diethylaminoethylmethacrylate, acrylic acid, methyl acrylate, ethyl acrylate, n-butylacrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecylacrylate, 2-ethylhexyl acrylate, stearyl acrylate, behenyl acrylate,2-chloroethyl acrylate, phenyl acrylate, vinyl methyl ether, vinyl ethylether, vinyl isobutyl ether, vinyl methyl ketone, vinyl hexyl ketone,methyl isopropenyl ketone, vinyl naphthalene, acrylonitrile,methacrylonitrile, and acrylamide.

Examples of the resin that can be used in the pigment composition arethe same as those that can be used as the binder resin for the toner ofthe present invention. Examples thereof include styrene-methacrylic acidcopolymers, styrene-acrylic acid copolymers, polyester resins, epoxyresins, and styrene-butadiene copolymers. Two or more of thesedispersion media may be mixed and used. The pigment composition can beisolated by a common method, for example, filtration, decantation, orcentrifugation. The solvent may be removed by washing.

An auxiliary agent may be added to the pigment composition duringproduction. Examples of the auxiliary agent include a surfactant, adispersant, a filler, a standardizer, a resin, a wax, a defoaming agent,an antistatic agent, an antidust agent, an extender, a shading colorant,a preservative, a drying inhibitor, a rheology controller, a humectant,an antioxidant, a UV absorber, a photostabilizer, and any combination ofthese. The compound having an azo skeleton structure may be added inadvance during production of the bulk pigment.

Toner particles are produced by a suspension polymerization method inthe following manner, for example. The pigment composition describedabove, a polymerizable monomer, a wax component, a polymerizationinitiator, and the like are mixed to prepare a polymerizable monomercomposition. Then the polymerizable monomer composition is dispersed ina water-based medium to form particles of the polymerizable monomercomposition. Then the polymerizable monomer in the particles of thepolymerizable monomer composition is polymerized in the water-basedmedium so as to obtain toner particles.

The polymerizable monomer composition in the above-described step may beprepared by mixing a dispersion prepared by dispersing the pigmentcomposition in a first polymerizable monomer with a second polymerizablemonomer. In other words, the pigment composition is thoroughly dispersedin the first polymerizable monomer and then mixed with the secondpolymerizable monomer along with other toner materials so that themagenta pigment can be more satisfactorily dispersed in the tonerparticles.

Commonly used polymerization initiators can be used as thepolymerization initiator used in the suspension polymerization methoddescribed above. Examples thereof include azo compounds, organicperoxides, inorganic peroxides, organic metal compounds, andphotopolymerization initiators. Specific examples thereof includeazo-based polymerization initiators such as2,2′-azobis(isobutyronitrile), 2,2′-azobis(2-methylbutyronitrile),2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile),2,2′-azobis(2,4-dimethylvaleronitrile), anddimethyl-2,2′-azobis(isobutyrate), organic peroxide-based polymerizationinitiators such as benzoyl peroxide, di-tert-butyl peroxide, tert-butylperoxyisopropyl monocarbonate, tert-hexylperoxy benzoate, andtert-butylperoxy benzoate, inorganic peroxide-based polymerizationinitiators such as potassium persulfate and ammonium persulfate, andinitiators based on hydrogen peroxide-ferrous iron, BPO-dimethylaniline,and cerium(IV) salt-alcohol. Examples of the photopolymerizationinitiator include acetophenones, benzoin ethers, and ketals. Thesepolymerization initiators may be used alone or in combination.

The concentration of the polymerization initiator is preferably 0.1 to20 parts by mass and more preferably 0.1 to 10 parts by mass relative to100 parts by mass of the polymerizable monomer. The type of thepolymerization initiator depends on the polymerization method. One or amixture of two or more polymerization initiators is used by consideringthe 10 hour half-life temperature.

The water-based medium used in the suspension polymerization methodabove may contain a dispersion stabilizer. Any common inorganic ororganic dispersion stabilizer can be used as the dispersion stabilizer.Examples of the inorganic dispersion stabilizer include calciumphosphate, magnesium phosphate, aluminum phosphate, zinc phosphate,magnesium carbonate, calcium carbonate, calcium hydroxide, magnesiumhydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate,barium sulfate, bentonite, silica, and alumina. Examples of the organicdispersion stabilizer include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium saltsof carboxymethyl cellulose, and starch. A nonionic, anionic, or cationicsurfactant can also be used. Examples thereof include sodium dodecylsulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodiumoctyl sulfate, sodium oleate, sodium laurate, potassium stearate, andcalcium oleate.

Of the dispersion stabilizers listed above, sparingly water-solubleinorganic dispersion stabilizers soluble in acids are preferably used inthe present invention. In preparing a water-based dispersion medium byusing a sparingly water-soluble inorganic dispersion stabilizer in thepresent invention, 0.2 to 2.0 parts by mass of the dispersion stabilizermay be used relative to 100 parts by mass of the polymerizable monomerfrom the viewpoint of stability of droplets of the polymerizable monomercomposition in the water-based medium. In the present invention, 300 to3000 parts by mass of water may be used relative to 100 parts by mass ofthe polymerizable monomer composition to prepare a water-based medium.

In preparing a water-based medium in which the sparingly water-solubleinorganic dispersion stabilizer is dispersed, a commercially availabledispersion stabilizer may be directly used to conduct dispersion.However, it is preferable that the sparingly water-soluble inorganicdispersion stabilizer is generated in water under high speed stirring.In this case, dispersion stabilizer particles, that are fine and haveuniform particle size, can be obtained. For example, when calciumphosphate is used as the dispersion stabilizer, an aqueous sodiumphosphate solution and an aqueous calcium chloride solution may be mixedand stirred at high speed to form fine particles of calcium phosphate.As a result, a desired dispersion stabilizer can be obtained.

Toner particles of the present invention can also be obtained by asuspension granulation method. Since the production process of thesuspension granulation method does not include a heating step, the resinand the wax component are suppressed from becoming compatible to eachother which would otherwise be the case when a low melting point wax isused, and the decrease in glass transition temperature of the tonercaused by becoming compatible can be prevented. The suspensiongranulation method allows a wide range of options of toner materials forthe binder resin and it is easy to use a polyester resin, which isgenerally considered as offering good fixability, as a main component.Accordingly, the suspension granulation method is advantageous inproducing a toner that has a resin composition not suitable for asuspension polymerization method.

Toner particles are produced by the suspension granulation methoddescribed above in the following manner. First, the pigment composition,a binder, resin, a wax component, and the like are mixed in a solvent toprepare a solvent composition. The solvent composition is dispersed in awater-based medium to form particles of the solvent composition and tothereby obtain a toner particle suspension. The suspension is heated orevacuated to remove the solvent to obtain toner particles.

The solvent composition in the above-described step may be prepared bymixing a dispersion prepared by dispersing the pigment composition in afirst solvent with a second solvent. In other words, the pigmentcomposition is thoroughly dispersed in the first solvent and then mixedwith the second solvent along with other toner materials so that themagenta pigment can be more satisfactorily dispersed in the tonerparticles.

Examples of the solvent that can be used in the suspension granulationmethod include hydrocarbons such as toluene, xylene, and hexane,halogen-containing hydrocarbons such as methylene chloride, chloroform,dichloroethane, trichloroethane, and carbon tetrachloride, alcohols suchas methanol, ethanol, butanol, and isopropyl alcohol, polyhydricalcohols such as ethylene glycol, propylene glycol, diethylene glycol,and triethylene glycol, cellosolves such as methyl cellosolve and ethylcellosolve, ketones such as acetone, methyl ethyl ketone, and methylisobutyl ketone, ethers such as benzyl alcohol ethyl ether, benzylalcohol isopropyl ether, and tetrahydrofuran, and esters such as methylacetate, ethyl acetate, and butyl acetate. These may be used alone or asa mixture of two or more. Among these, a solvent that has a low boilingpoint and is capable of sufficiently dissolving the binder resin ispreferred in order to facilitate removal of the solvent from the tonerparticle suspension.

The amount of the solvent used is preferably in the range of 50 to 5000parts by mass and more preferably in the range of 120 to 1000 parts bymass relative to 100 parts by mass of the binder resin.

The water-based medium used in the suspension granulation methoddescribed above may contain a dispersion stabilizer. Any commoninorganic or organic dispersion stabilizer can be used as the dispersionstabilizer. Examples of the inorganic dispersion stabilizer includecalcium phosphate, calcium carbonate, aluminum hydroxide, calciumsulfate, and barium carbonate. Examples of the organic dispersionstabilizer include surfactants such as polyvinyl alcohol, methylcellulose, hydroxyethyl cellulose, ethyl cellulose, sodium salts ofcarboxymethyl cellulose, water-soluble polymers such as polysodiumacrylate and polysodium methacrylate, anionic surfactants such as sodiumdodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, sodiumlaurate, and potassium stearate, cationic surfactants such as laurylamine acetate, stearyl amine acetate, and lauryl trimethyl ammoniumchloride, amphionic surfactants such as lauryldimethylamine oxide, andnonionic surfactants such as polyoxyethylene alkyl ether,polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl amine.

Relative to 100 parts by mass of the binder resin, 0.01 to 20 parts bymass of the dispersant may be used from the viewpoint of stability ofthe droplets of the solvent composition in the water-based medium.

The weight-average particle size (hereinafter “D4) of the toner of thepresent invention is within the range of 3.00 to 15.0 μm and morepreferably within the range of 4.00 to 12.0 μm. A high-definition imagecan be easily obtained while maintaining charge stability if theparticle size is within this range.

The ratio of D4 of the toner to the number-average particle size(hereinafter “D1”) (hereinafter this ratio is referred to as D4/D1) is1.35 or less and preferably 1.30 or less in order to suppress foggingand improve transfer efficiency while maintaining high resolution.

D4 and D1 of the toner of the present invention are adjusted indifferent ways depending on the method for producing the tonerparticles. In the case where a suspension polymerization method is usedto produce toner particles, D4 and D1 can be adjusted by controlling,for example, the dispersant concentration used in preparing thewater-based dispersion medium, the rate of stirring during the reaction,and the time of stirring during the reaction.

The toner of the present invention may be magnetic or nonmagnetic. If amagnetic toner is to be used, a magnetic material may be mixed with thetoner particles of the toner of the present invention. Examples of themagnetic material include iron oxides such as magnetite, maghemite, andferrite, iron oxides containing other metal oxides, metals such as Fe,Co, and Ni, and alloys and mixtures of these metals with Al, Co, Cu, Pb,Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, and V. The magneticmaterial most suited for the purposes of the present invention is finepowder of triiron tetraoxide or γ-diiron trioxide.

These magnetic materials preferably have an average particle size of 0.1to 2 μm and more preferably 0.1 to 0.3 μm, and preferably exhibit acoercive force of 1.6 to 12 kA/m, a saturation magnetization of 5 to 200Am²/kg and more preferably 50 to 100 Am²/kg, and a residualmagnetization of 2 to 20 Am²/kg under application of a 795.8 kA/mmagnetic field from the viewpoint of development properties of thetoner.

To 100 parts by mass of the binder resin, 10 to 200 parts by mass andpreferably 20 to 150 parts by mass of the magnetic material is used.

EXAMPLES

The present invention will now be described in further detail by usingExamples and Comparative Examples. The present invention is not limitedby the examples below. In the description below, “part” and “%” are on amass basis unless otherwise noted.

The measurement methods employed in the synthetic examples are asfollows.

(1) Determination of Molecular Weight

The molecular weight of a compound having a polymer portion and an azoskeleton structure was calculated on a polystyrene basis by sizeexclusion chromatography (SEC). The molecular weight was determined bySEC as follows.

A sample was added to an eluent described below so that the sampleconcentration was 1.0% to prepare a solution. The solution was leftstanding still for 24 hours at room temperature and filtered through asolvent-resistant membrane filter with a 0.2 μm pore size to prepare asample solution. The sample solution was measured under the followingconditions.

Instrument: High speed GPC device HLC-8220GPC [produced by TosohCorporation]Column: Two column combination of LF-804

Eluant: THF

Flow rate: 1.0 ml/minOven temperature: 40° C.Amount of injected sample: 0.025 ml

In calculating the molecular weight of the sample, molecular weightcalibration curves obtained from standard polystyrene resins [productsof Tosoh Corporation, TSK standard polystyrene F-850, F-450, F-288,F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000,and A-500] were used.

(2) Acid Value Measurement

The acid value of the compound having a polymer portion and an azoskeleton structure was determined by the following method.

The basic procedure was carried out according to JIS K-0070.

1) First, 0.5 to 2.0 g of the sample is accurately weighed. This mass isassumed to be M (g).2) The sample is placed in a 50 ml beaker and dissolved by addition of25 ml of a tetrahydrofuran/ethanol (2:1) mixed solution.3) Titration is conducted with a potentiometric titrator by using a 0.1mol/l ethanol solution of KOH. For example, automatic titrator COM-2500produced by Hiranuma Sangyo Corporation can be used.4) The amount of the KOH solution used in this step is assumed to be S(ml). At the same time, the blank is measured and the amount of the KOHsolution used is assumed to be B (ml).5) The acid value is calculated by the following formula where frepresents a factor of the KOH solution.

${{Acid}\mspace{14mu} {{value}\left\lbrack {{mg}\mspace{14mu} {{KOH}/g}} \right\rbrack}} = \frac{\left( {S - B} \right) \times f \times 5.61}{M}$

(3) Composition Analysis

The structure of the compound having a polymer portion and an azoskeleton structure is identified by using the following instrument.

¹H NMR

ECA-400 produced by JEOL Ltd. (solvent used: deuterated chloroform)

Example 1

A compound having an azo skeleton was obtained through the followingmethod.

Production Example of Compound (116)

A compound (116) having an azo skeleton represented by structuralformula below was produced by the following scheme.

First, 3.11 parts of p-nitroaniline (29) was added to 30 parts ofchloroform, the mixture was cooled with ice to 10° C. or lower, and 1.89parts of diketene (30) was added thereto, followed by stirring for 2hours at 65° C. After completion of the reaction, chloroform extractionand condensation were performed to obtain 4.70 parts (yield: 94.0%) of acompound (31).

Next, 40.0 parts of methanol and 5.29 parts of concentrated hydrochloricacid were added to 4.25 parts of dimethyl 2-aminoterephthalate (32) andthe mixture was cooled with ice to 10° C. or lower. To the resultingsolution, 2.10 parts of sodium nitrite dissolved in 6.00 parts of waterwas added and the reaction was carried out at the same temperature for 1hour. Next, 0.990 parts of sulfamic acid was added thereto, followed bystirring for 20 minutes (diazonium salt solution). To 70.0 of methanol,4.51 parts of the compound (31) was added. The mixture was cooed withice to 10° C. or lower and the diazonium salt solution was added to themixture. Thereto, 5.83 parts of sodium acetate dissolved in 7.00 partsof water was added and the reaction was carried out for 2 hours at 10°C. or lower. After completion of the reaction, 300 parts of water wasadded and stirring was conducted for 30 minutes. Solid matter wasfiltered out and purified by a recrystallization method inN,N-dimethylformamide. As a result, 8.71 parts (yield: 96.8%) of acompound (33) was obtained.

Next, 8.58 parts of the compound (33) and 0.40 parts of palladium-activecarbon (5% palladium) were added to 150 parts of N,N-dimethylformamideand the resulting mixture was stirred in a hydrogen gas atmosphere(reaction pressure: 0.1 to 0.4 MPa) at 40° C. for 3 hours. Aftercompletion of the reaction, the solution was filtered and condensed toobtain 6.99 parts (yield: 87.5%) of a compound (34).

Next, 6.50 parts of the compound (34) was added to 30.0 parts ofchloroform and the resulting mixture was cooled with ice to 10° C. orlower. To the mixture, 0.95 parts of diketene (30) was added, followedby stirring at 65° C. for 2 hours. After completion of the reaction,chloroform extraction and condensation were conducted to obtain 7.01parts (yield: 94.2%) of an azo compound intermediate (35).

Next, 15.0 parts of methanol and 1.48 parts of concentrated hydrochloricacid were added to 1.78 parts of 2-(4-aminophenyl)ethanol (36) and theresulting mixture was cooed with ice to 10° C. or lower. To theresulting solution, 1.08 parts of sodium nitrite dissolved in 3.00 partsof water was added and the reaction was carried out at the sametemperature for 1 hour. To the resulting solution, 0.380 parts ofsulfamic acid was added, followed by further stirring for 20 minutes(diazonium salt solution). To 70.0 parts of N,N-dimethylformamide, 7.18parts of potassium carbonate dissolved in 7.00 parts of water and 6.50parts of the compound (35) were added. The resulting mixture was cooledwith ice to 10° C. or lower and the diazonium salt solution was addedthereto. The reaction was carried out for 2 hours at 10° C. or lower.After completion of the reaction, 300 parts of water was added, followedby stirring for 30 minutes. Solid matter was filtered out and purifiedby a recrystallization method from N,N-dimethylformamide. As a result,7.62 parts (yield: 91.0%) of a compound (37) was obtained.

Next, 2.00 parts of the compound (37) was added to 20.0 parts ofchloroform. The resulting mixture was cooled with ice to 10° C. or lowerand 0.855 parts of 2-bromoisobutyrylbromide (38) was added thereto,followed by stirring at 65° C. for 2 hours. After completion of thereaction, chloroform extraction and condensation were conducted toobtain 2.26 parts (yield: 92.0%) of an intermediate (39).

Next, 0.684 parts of the compound (39), 27.3 parts of styrene (40),0.305 parts of N,N,N′,N″,N″-pentamethyldiethylenetriamine, and 0.124parts of copper(I) bromide were added to 10.0 parts ofN,N-dimethylformamide. Then stirring was conducted in a nitrogenatmosphere at 100° C. for 7.5 hours. After completion of the reaction,chloroform extraction and purification through methanol reprecipitationwere conducted to obtain 8.50 parts (yield: 85.0%) of a compound (116).

The product obtained as such was analyzed by the instruments describedabove to confirm the structure. The analytic results are as follows.

Analytic Results of the Compound (116) Having an Azo Skeleton

[1] Results of molecular weight measurement (GPC)Weight-average molecular weight (Mw)=15117, number-average molecularweight (Mn)=12910[2] Results of acid value measurement0 mgKOH/g[3] Results of ¹H NMR (400 MHz, CDCl₃, room temperature) (see FIG. 1)

δ [ppm]=15.65 (s, 1H), 14.77 (s, 1H), 11.40 (s, 1H), 11.41 (s, 1H), 8.62(s, 1H), 8.15 (d, 1H), 7.79 (d, 1H), 7.74 (d, 2H), 7.64 (d, 2H),7.37-6.27 (m, 738H), 4.07 (s, 3H), 3.98 (s, 3H), 3.73 (br, 2H),2.72-2.52 (m, 9H), 2.47-1.05 (m, 458H), 1.01-0.78 (m, 6H)

Production Example of Compound (129)

A compound (129) having an azo skeleton was produced by the followingscheme.

First, 100 parts of propylene glycol monomethyl ether was heated undernitrogen purge and refluxed at a liquid temperature of 120° C. orhigher. Thereto, a mixture of 190 parts of styrene (40), 10.0 parts ofacrylic acid (41), and 1.00 part of tert-butylperoxybenzoate [organicperoxide-based polymerization initiator produced by NOF Corporation,trade name: PERBUTYL Z] was added dropwise for 3 hours. After completionof the dropwise addition, the solution was stirred for 3 hours anddistilled at normal pressure while heating the solution to a liquidtemperature of 170° C. After reaching the liquid temperature of 170° C.,distillation was conducted at a reduced pressure of 1 hPa for 1 hour toremove the solvent and obtain a resin solid product. The solid productwas dissolved in tetrahydrofuran and purified by reprecipitation inn-hexane to obtain 185 parts (yield: 92.5%) of a compound (42).

To 15.0 parts of chloroform, 3.00 parts of the compound (42) and 184parts of oxalyl chloride were added, followed by stirring in a nitrogengas atmosphere at room temperature for 5 hours. To the resultingsolution, 0.644 parts of p-phenylenediamine (43) dissolved in 10.0 partsof chloroform and 5.00 parts of N,N-dimethylformamide was addeddropwise, followed by stirring in a nitrogen gas atmosphere at roomtemperature for 2 hours. After completion of the reaction, the solutionwas fractionated with chloroform/water, condensed, and purified throughreprecipitation in methanol. As a result, 2.98 parts (yield: 90.3%) of acompound (44) was obtained.

Next, 10.0 parts of tetrahydrofuran and 0.252 parts of concentratedhydrochloric acid were added to 1.00 part of the compound (44) and theresulting mixture was cooled with ice to 0° C. or lower. To thissolution, 0.0900 parts of sodium nitrite dissolved in 0.270 parts ofwater was added and the reaction was carried out at the same temperaturefor 1 hour. Then 0.063 parts of sulfamic acid was added, followed byfurther stirring for 20 minutes (diazonium salt solution). To 15.0 partsof N,N-dimethylformamide, 0.446 parts of potassium carbonate dissolvedin 1.50 parts of water and 0.354 parts of the compound (35) were added.The resulting mixture was cooled with ice to 10° C. or lower, thediazonium salt solution was added thereto, and the reaction was carriedout at 10° C. or lower for 4 hours. After completion of the reaction,300 parts of water was added, followed by stirring for 30 minutes. Solidmatter was filtered out, dissolved in chloroform, and purified throughreprecipitation in methanol. As a result, 0.970 parts (yield: 97.0%) ofa compound (129) was obtained.

The product obtained as such was analyzed by the instruments describedabove to confirm the structure. The analytic results are as follows.

Analytic Results of the Compound (129) Having an Azo Skeleton

[1] Results of molecular weight measurement (GPC)Weight-average molecular weight (Mw)=32442, number-average molecularweight (Mn)=18329[2] Results of acid value measurement0 mgKOH/g[3] Results of ¹H NMR (400 MHz, CDCl₃, room temperature) (see FIG. 2)

δ [ppm]=15.57 (s, 1H), 14.70 (s, 1H), 11.44 (s, 1H), 11.33 (s, 1H), 8.54(s, 1H), 8.07 (d, 1H), 7.71 (d, 1H), 7.65 (d, 2H), 7.56 (d, 2H),7.19-6.43 (m, 136H), 4.00 (s, 3H), 3.91 (s, 3H), 2.61 (s, 3H), 2.50 (s,3H), 1.76-0.81 (m, 97H)

Production Example of Compound (174)

A compound (174) having an azo skeleton was produced by the followingscheme.

To 0.395 parts of methyl 2-bromopropionate (45), 60.0 parts of styrene(40), 1.47 parts of N,N,N′,N″,N″-pentamethyldiethylenetriamine, and0.493 parts of copper(I) bromide were added, followed by stirring in anitrogen gas atmosphere at 100° C. for 5 hours. After completion of thereaction, chloroform extraction and purification through reprecipitationin methanol were conducted. As a result, 52.4 parts (yield: 81.9%) of acompound (46) was obtained.

To 150 parts of dioxane, 1.00 parts of the compound (46) was added. Theresulting mixture was stirred at 110° C. and a mixture of 5.00 parts ofconcentrated hydrochloric acid and 30 parts of dioxane was addedthereto, followed by stirring in a nitrogen gas atmosphere at 110° C.for 5 hours. After completion of the reaction, chloroform extraction andpurification through reprecipitation in methanol were conducted. As aresult, 0.98 parts (yield: 98.0%) of a compound (47) was obtained.

Next, 1.00 parts of the compound (47) and 0.0160 parts of oxalylchloride were added to 5.00 parts of chloroform and the resultingmixture was stirred in a nitrogen gas atmosphere at room temperature for5 hours. To the resulting solution, 0.0670 parts of p-phenylenediamine(43) dissolved in 10.0 of chloroform and 5.00 parts ofN,N-dimethylformamide was added dropwise, followed by stirring in anitrogen gas atmosphere at 60° C. for 2 hours. After completion of thereaction, the solution was fractionated with chloroform/water,condensed, and purified through reprecipitation in methanol. As aresult, 0.970 parts (yield: 97.0%) of a compound (48) was obtained.

Next, 50.0 parts of p-phenylenediamine (43) and 35.0 parts of acetonewere added to 300 parts of chloroform. The resulting mixture was cooledwith ice to 10° C. or lower and 72.0 parts of diketene (30) was addedthereto, followed by stirring at 65° C. for 2 hours. After completion ofthe reaction, chloroform extraction and condensation were conducted toobtain 121 parts (yield: 97.4%) of a compound (49).

Next, to 4.00 parts of the compound (49), 40.0 parts of THF and 0.127parts of concentrated hydrochloric acid were added, and the resultingmixture was cooled with ice to 10° C. or lower. To the resultingsolution, 0.005 parts of sodium nitrite dissolved in 1.70 parts of waterwas added and the reaction was carried out at the same temperature for 1hour. Then 0.0320 parts of sulfamic acid was added, followed by furtherstirring for 20 minutes (diazonium salt solution). To 70.0 parts ofmethanol, 0.230 parts of the potassium sulfate dissolved in 1.00 part ofwater, and 0.0460 parts of the compound (48) were added and theresulting mixture was cooled with ice to 10° C. or lower. The diazoniumsalt solution was added thereto and the reaction was carried out at 10°C. or lower for 2 hours. After completion of the reaction, 300 parts ofwater was added thereto, followed by stirring for 30 minutes. Solidmatter was filtered out and purified through reprecipitation inmethanol. As a result, 3.80 parts (yield: 95.0%) of a compound (174) wasobtained.

Analytic Results of the Compound (174) Having an Azo Skeleton

[1] Results of molecular weight measurement (GPC)Weight-average molecular weight (Mw)=31686, number-average molecularweight (Mn)=22633[2] Results of acid value measurement0 mgKOH/g[3] Results of ¹H NMR (400 MHz, CDCl₃, room temperature) (see FIG. 3)

δ [ppm]=14.78 (s, 2H), 11.50 (s, 2H), 7.63 (d, 4H), 7.29-6.37 (m,1192H), 2.56 (s, 6H), 2.18-0.99 (m, 839H)

Production Example of Compound (176)

A compound (176) having an azo skeleton represented by a structure belowwas produced by the following scheme.

First, a compound (48) was obtained by the same operation as ProductionExample of compound (174).

Next, to 10.0 parts of N,N-dimethylformamide, 0.500 parts of1,3,5-triaminobenzene (50) and 0.345 parts of triethylamine were added,followed by stirring at room temperature. Next, 0.949 parts of diketene(30) was added thereto, followed by stirring at 50° C. for 2 hours.After completion of the reaction, 300 parts of water was added, followedby stirring for 30 minutes and solid matter was filtered out. As aresult, 1.41 parts (yield: 92.8%) of a compound (51) was obtained.

Next, to 4.00 of the compound (48), 20 parts of DMF, 20.0 parts of THF,and 0.130 parts of concentrated hydrochloric acid were added. Theresulting mixture was cooled with ice to 10° C. or lower. To thissolution, 0.0450 parts of sodium nitrite dissolved in 0.136 parts ofwater was added and the reaction was carried out at the same temperaturefor 1 hour. Thereto, 0.0320 parts of sulfamic acid was added, followedby further stirring for 20 minutes (diazonium salt solution). To 15.0 ofDMF, 0.225 parts of potassium acetate dissolved in 1.00 part of waterand 0.0440 parts of the compound (51) were added and the resultingmixture was cooled with ice to 10° C. or lower. Thereto, the diazoniumsalt solution was added and the reaction was carried out at 10° C. orlower for 2 hours. After completion of the reaction, 300 parts of waterwas added, followed by stirring for 30 minutes, and solid matter wasfiltered out and purified through recrystallization inN,N-dimethylformamide so as to obtain 3.78 parts (yield: 94.5%) of acompound (176).

Analytic Results of the Compound (176) Having an Azo Skeleton

[1] Results of molecular weight measurement (GPC)Weight-average molecular weight (Mw)=48989, number-average molecularweight (Mn)=28481[2] Results of acid value measurement0 mgKOH/g[3] Results of ¹H NMR (400 MHz, CDCl₃, room temperature) (see FIG. 4)

δ [ppm]=14.73 (s, 3H), 11.53 (s, 3H), 7.79 (s, 3H), 7.27-6.31 (m,2175H), 2.52 (s, 9H), 2.12-0.81 (m, 1461H)

The same operation as the synthetic example of the compounds (116),(129), (174), and (176) having azo skeletons was performed to producecompounds (101) to (115), (117) to (128), (130) to (173), (175), and(177) to (179) having azo skeletons.

The polymer portion is shown in Table 1 and the compounds having azoskeletons are shown in Tables 2-1 to 2-4 below.

TABLE 1 Polymer Sequential portion arrangement No. No. No. No. number ofmonomers of X of Y₁ of Y₂ of Z R₄₆ R₄₇ R₄₈ R₄₉ R₅₀ R₅₁ R-1 α-W-polyX 950 0 0 H — — — — — R-2 α-W-polyX 149 0 0 0 H — — — — — R-3 α-W-polyY₁ 0101 0 0 — H COOC₄H₉(n) — — — R-4 α-W-poly(X-co-Y₁) 71 18 0 0 H HCOOC₄H₉(n) — — — R-5 α-W-poly(X-co-Y₁) 18 88 0 0 H H COOC₄H₉(n) — — —R-6 α-W-poly(X-co-Y₁) 71 18 0 0 H H CONH₂ — — — R-7 α-W-poly(X-co-Y₁) 7118 0 0 H H COOCH₃ — — — R-8 α-W-poly(X-co-Y₁) 71 18 0 0 H H COOBn — — —R-9 poly(X-co-Y₁-co-Z) 141 30 0 11 H H COOC₄H₉(n) — — H R-10poly(X-co-Y₁-co-Z) 15 11 0 7 CH₃ CH₃ COOC₄H₉(n) — — H R-11poly(X-co-Y₁-co-Z) 220 4 0 4 H — COOCH₃ — — H R-12 poly(X-co-Y₁-co-Z) 575 0 3 H H COOCH₂CH(C₂H₅)C₄H₉ — — H R-13 poly(X-co-Y₁-co-Z) 49 4 0 2 H HCOOC₁₈H₃₇(n) — — H R-14 poly(X-co-Y₁-co-Z) 58 3 0 3 H H COOC₂₂H₄₅(n) — —H R-15 poly 75 13 3 3 H H COOCH₃ H COOC₂₂H₄₅(n) H (X-co-Y₁-co-Y₂-co-Z)R-16 poly 59 28 4 3 H H COOC₄H₉(n) H COOC₂₂H₄₅(n) H (X-co-Y₁-co-Y₂-co-Z)R-17 poly(X-co-Z) 220 0 0 8 H — — — — H R-18 poly(X-co-Z) 1174 0 0 384 H— — — — H R-19 poly(Y₁-co-Z) 0 90 0 10 — H COOC₄H₉(n) — — H R-20polyX-b-polyZ 84 0 0 5 H — — — — H R-21 poly(X-co-Y₁)-b-polyZ 74 14 0 2H H COOC₄H₉(n) — — HIn Table 1, the prefix α represents the terminal group on the left ofthe structure. W represents a COOH group. X, Y₁, Y₂, and Z respectivelyrepresent structures indicated below. Bn represents an unsubstitutedbenzyl group. (n) indicates that the alkyl group is linear.

[in formula (X), R₄₆ represents a hydrogen atom or an alkyl group]

[in formula (Y₁), R₄₇ represents a hydrogen atom or an alkyl group andR₄₈ represents a carboxylic acid ester group or a carboxylic acid amidegroup]

[in formula (Y₂), R₄₉ represents a hydrogen atom or an alkyl group andR₅₀ represents a carboxylic acid ester group or a carboxylic acid amidegroup]

[in formula (Z), R₅₁ represents a hydrogen atom or an alkyl group]

TABLE 2-1 Linking Substitution position to Number of positions ofPolymer polymer introduced acetamide Compound portion portion m n unitsgroups R₁ R₉ R₁₀ R₁₁ 101 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 102R-3 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 103 R-4 W 4 1 1 1,4- 2,3,5,6-HCH₃ CH₃ COOCH₃ 104 R-5 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 105 R-6 W 41 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 106 R-7 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 107 R-8 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 108 R-1 W 4 1 11,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 109 R-4 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 110 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 111 R-4 W 4 1 11,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 112 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 113 R-4 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 114 R-1 W 4 1 11,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 115 R-4 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 116 R-2 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 117 R-4 W 4 1 11,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 118 R-9 Z 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 119 R-9 Z 4 1 11 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 120 R-10 Z 4 1 21,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ Compound R₁₂ R₁₃ R₁₄ R₁₅ R₁₆ R₁₇ R₁₈ R₁₉R₂₀ 101 H H COOCH₃ H H H L₁ H H 102 H H COOCH₃ H H H L₁ H H 103 H HCOOCH₃ H H H L₁ H H 104 H H COOCH₃ H H H L₁ H H 105 H H COOCH₃ H H H L₁H H 106 H H COOCH₃ H H H L₁ H H 107 H H COOCH₃ H H H L₁ H H 108 H HCOOCH₃ H H H L₂ H H 109 H H COOCH₃ H H H L₂ H H 110 H H COOCH₃ H H H L₃H H 111 H H COOCH₃ H H H L₃ H H 112 H H COOCH₃ H H H L₄ H H 113 H HCOOCH₃ H H H L₄ H H 114 H H COOCH₃ H H H L₅ H H 115 H H COOCH₃ H H H L₅H H 116 H H COOCH₃ H H H L₆ H H 117 H H COOCH₃ H H H L₆ H H 118 H HCOOCH₃ H H H L₇ H H 119 H H COOCH₃ H H H L₇ H H 120 H H COOCH₃ H H H L₇H H

TABLE 2-2 Linking Substitution position to Number of positions ofPolymer polymer introduced acetamide Compound portion portion m n unitsgroups R₁ R₉ R₁₀ R₁₁ 121 R-10 Z 4 1 7 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 122R-11 Z 4 1 4 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 123 R-12 Z 4 1 3 1,4-2,3,5,6-H CH₃ CH₃ COOCH₃ 124 R-13 Z 4 1 2 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃125 R-14 Z 4 1 3 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 126 R-15 Z 4 1 3 1,4-2,3,5,6-H CH₃ CH₃ COOCH₃ 127 R-16 Z 4 1 3 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃128 R-11 Z 4 1 6 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 129 R-11 Z 4 1 8 1,4-2,3,5,6-H CH₃ CH₃ COOCH₃ 130 R-12 Z 4 1 197 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 131 R-13 Z 4 1 8 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 132 R-14 Z 4 1 51,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 133 R-15 Z 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 134 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 135 R-1 W 4 1 11,4- 2,3,5,6-H C₆CH₁₃(n) Ph COOCH₃ 136 R-1 W 4 1 1 1,4- 2-OH CH₃ CH₃COOCH₃ 3,6-H 5-Cl 137 R-1 W 4 1 1 1,4- 2-OCH₃ CH₃ CH₃ COOCH₃ 3,5,6-H 138R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 139 R-1 W 4 1 1 1,4- 2-CF₃ CH₃CH₃ COOCH₃ 3,5,6-H 140 R-1 W 4 1 1 1,4- 2-CN CH₃ CH₃ COOCH₃ 3,5,6-HCompound R₁₂ R₁₃ R₁₄ R₁₅ R₁₆ R₁₇ R₁₈ R₁₉ R₂₀ 121 H H COOCH₃ H H H L₇ H H122 H H COOCH₃ H H H L₇ H H 123 H H COOCH₃ H H H L₇ H H 124 H H COOCH₃ HH H L₇ H H 125 H H COOCH₃ H H H L₇ H H 126 H H COOCH₃ H H H L₇ H H 127 HH COOCH₃ H H H L₇ H H 128 H H COOCH₃ H H H L₇ H H 129 H H COOCH₃ H H HL₇ H H 130 H H COOCH₃ H H H L₇ H H 131 H H COOCH₃ H H H L₇ H H 132 H HCOOCH₃ H H H L₇ H H 133 H H COOCH₃ H H H L₇ H H 134 H H COOCH₃ H H H L₇H H 135 H H COOCH₃ H H H L₈ H H 136 H H COOCH₃ H H H L₈ H H 137 H HCOOCH₃ H H H L₈ H H 138 H H COOCH₃ H H H L₈ H H 139 H H COOCH₃ H H H L₈H H 140 H H COOCH₃ H H H L₈ H H

TABLE 2-3 Linking Substitution position to Number of positions ofPolymer polymer introduced acetamide Compound portion portion m n unitsgroups R₁ R₉ R₁₀ R₁₁ 141 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ CH₃ 142 R-1W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 143 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃H 144 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 145 R-1 W 4 1 1 1,4-2,3,5,6-H CH₃ CH₃ COOH 146 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOC₂H₅147 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOPr(n) 148 R-1 W 4 1 1 1,4-2,3,5,6-H CH₃ CH₃ COOPr(i) 149 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ CONH₂150 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ CONHCH₃ 151 R-1 W 4 1 1 1,4-2,3,5,6-H CH₃ CH₃ CONHC₂H₅ 152 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃CONHPr(i) 153 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ CONHPr(n) 154 R-1 W 4 11 1,4- 2,3,5,6-H CH₃ CH₃ CON(C₂H₅)₂ 155 R-4 W 4 1 1 1,4- 2,3,5,6-H CH₃CH₃ H 156 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ CONH₂ 157 R-1 W 4 1 1 1,4-2,3,5,6-H CH₃ CH₃ H 158 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 159 R-1 W 41 1 1,4- 2,3,5,6-H CH₃ CH₃ H 160 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ HCompound R₁₂ R₁₃ R₁₄ R₁₅ R₁₆ R₁₇ R₁₈ R₁₉ R₂₀ 141 H Cl H H H H L₈ H H 142CF₃ H H H H H L₈ H H 143 H OCH₂CH₃ H H H H L₈ H H 144 CN H H H H H L₈ HH 145 H H COOH H H H L₈ H H 146 H H COOC₂H₅ H H H L₈ H H 147 H HCOOPr(n) H H H L₈ H H 148 H H COOPr(i) H H H L₈ H H 149 H H CONH₂ H H HL₈ H H 150 H H CONHCH₃ H H H L₈ H H 151 H H CONHC₂H₅ H H H L₈ H H 152 HH CONHPr(i) H H H L₈ H H 153 H H CONHPr(n) H H H L₈ H H 154 H HCON(C₂H₅)₂ H H H L₈ H H 155 CONH₂ H H H H H L₈ H H 156 H H H H H H L₈ HH 157 CONH₂ H H H H H L₈ H H 158 H CONH₂ H H H H L₈ H H 159 CONH₂ H HOCH3 H H L₈ H H 160 CONHC₆H₅ H H OCH3 H H L₈ H H

TABLE 2-4 Linking Substitution position to Number of positions ofPolymer polymer introduced acetamide Compound portion portion m n unitsgroups R₁ R₉ R₁₀ R₁₁ 161 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 162 R-1 W4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 163 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H164 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 165 R-1 W 4 1 1 1,4- 2,3,5,6-HCH₃ CH₃ COOCH₃ 166 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 167 R-1 W 4 1 11,4- 2,3,5,6-H CH₃ CH₃ H 168 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 169R-1 W 4 1 1 1,3- 2,3,5,6-H CH₃ CH₃ COOCH₃ 170 R-1 W 4 1 1 1,2- 2,3,5,6-HCH₃ CH₃ COOCH₃ 171 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 172 R-1 W 41 1 1,4- 2,3,5,6-H CH₃ CH₃ COOCH₃ 173 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃COOCH₃ 174 R-1 W 4 1 1 1,4- 2,3,5,6-H CH₃ CH₃ H 175 R-1 W 4 1 1 1,4-2,3,5,6-H CH₃ CH₃ H 176 R-1 W 3 2 1 1,3,5- 2,4,6-H CH₃ CH₃ H 177 R-1 W 32 1 1,2,3- 4,5,6-H CH₃ CH₃ H 178 R-1 W 3 2 1 1,2,5- 2-CH₃ CH₃ CH₃ H 6-H179 R-1 W 3 2 1 1,3,5- 2,6-H CH₃ CH₃ H Compound R₁₂ R₁₃ R₁₄ R₁₅ R₁₆ R₁₇R₁₈ R₁₉ R₂₀ 161 CONHC₆H₅ H H H H H L₈ H H 162 CONHCH₃ H H H H H L₈ H H163 NHCOCH₃ H H H H H L₈ H H 164 CONH₂ H H OH H H L₈ H H 165 H H H H H HL₈ H H 166 COOCH₃ H H H H H L₈ H H 167 H COOCH₃ H H H H L₈ H H 168COOCH₃ H COOCH₃ H H H L₈ H H 169 H H COOCH₃ H H H L₈ H H 170 H H COOCH₃H H H L₈ H H 171 H H COOCH₃ H H L₈ H H H 172 H H COOCH₃ H L₈ H H H H 173H H COOCH₃ H H L₈ H L₈ H 174 H L₈ H H H H L₈ H H 175 L₈ H L₈ H H L₈ H L₈H 176 H L₈ H H H H L₈ H H 177 H L₈ H H H H L₈ H H 178 H L₈ H H H H L₈ HH 179 L₈ H L₈ H H L₈ H L₈ H

In Tables 2-1 to 2-4, m, n, R₁, and R₉ to R₂₀ respectively represent m,n, R₁ and R₉ to R₂₀ in formula (3) below; Pr represents an unsubstitutedpropyl group; Ph represents an unsubstituted phenyl group; (n) and (i)respectively represent a linear alkyl group and a branched alkyl group;a compound in which the bonding portion to the polymer portion is “W”forms a linking group L by bonding with a COOH group represented by W inthe polymer portion shown in Table 1; a compound in which the “linkingmoiety to the polymer portion” is indicated by “W” forms a linking groupL by bonding with a COOH group represented by “W” in the polymer portiondescribed in Table 1 and a compound in which the linking moiety to thepolymer portion is indicated by “Z” forms a linking group L by bondingwith a COOH group in the monomer “Z” in the polymer portion described inTable 1; L₁ to L₈ in Table 2 each represent a linking group L to thepolymer resin and are represented by the structural formula below:

[in formula (L₁), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₂), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₃), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₄), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₅), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₆), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₇), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)]

[in formula (L₈), “*” represents a linking moiety linking to the polymerportion indicated in Table 1 and “**” represents a linking moiety in theazo skeleton structure represented by formula (1)].

Example 2

A magenta pigment dispersion containing a magenta pigment and a compoundhaving an azo skeleton was prepared by the following method in a tonerproduction process that involves a suspension polymerization method.

Preparation Example 1 of Magenta Pigment Dispersion

Mixed were 30.0 parts of a pigment represented by formula (52) belowserving as a colorant, 3.0 parts of the compound (101) having an azoskeleton structure, 180 parts of styrene as a water-insoluble solvent,and 130 parts of glass beads (1 mm in diameter). The resulting mixturewas dispersed in an attritor (produced by Nippon Coke & Engineering Co.,Ltd.) for 3 hours and filtered through a mesh to obtain a magentapigment dispersion (DIS1).

Preparation Example 2 of Magenta Pigment Dispersion

Magenta pigment dispersions (DIS2) to (DIS79) were obtained as inPreparation Example 1 of magenta pigment dispersion except that thecompound (101) having an azo skeleton structure was changed to compounds(102) to (179) having azo skeleton structures.

Preparation Example 3 of Magenta Pigment Dispersion

Magenta pigment dispersions (DIS80), (DIS81), and (DIS82) were obtainedas in Preparation Example 1 of magenta pigment dispersion except thatthe pigment represented by formula (52) above was changed to pigmentsrepresented by formulae (53), (54), and (55) below.

Comparative Example 1

A magenta pigment dispersion that serves as a standard of evaluation anda magenta pigment dispersion for comparison were prepared by thefollowing method.

Preparation Example 1 of Magenta Pigment Dispersion for Standard

A magenta pigment dispersion (DIS83) for standard was obtained as inPreparation Example 1 of magenta pigment dispersion in Example 2 exceptthat the compound (101) having an azo skeleton structure was not added.

Preparation Example 2 of Magenta Pigment Dispersion for Standard

Magenta pigment dispersions (DIS84) to (DIS86) were obtained as inPreparation Example 3 of magenta pigment dispersion in Example 2 exceptthat the compound (101) having an azo skeleton structure was not added.

Preparation Example 1 of Magenta Pigment Dispersion for Comparison

A magenta pigment dispersion (DIS87) was obtained as in PreparationExample 1 of magenta pigment dispersion of Example 2 except that thecompound (101) having an azo skeleton structure was changed to DA-703-50(product of produced by Kusumoto Chemicals Ltd.) (comparativecompound 1) described in Japanese Patent Laid-Open No. 2006-30760.

Preparation Example 2 of Magenta Pigment Dispersion for Comparison

Magenta pigments dispersions (DIS88) to (DIS90) for comparison wereobtained as in Preparation Example 3 of magenta pigment dispersion ofExample 2 except that the compound (101) having an azo skeletonstructure was changed to comparative compound 1.

Example 3

The magenta pigment dispersions prepared as above were evaluated by thefollowing method.

Evaluation of Dispersibility in Magenta Pigment Dispersion

The magenta pigment dispersibility of the compound having an azoskeleton structure of the present invention was evaluated by performinga gloss test on coating films of magenta pigment dispersions. That is, amagenta pigment dispersion taken in a syringe was discharged on a sheetof super art paper (SA Kinfuji 180 kg, 80×160 produced by Oji HoldingsCorporation) so as to draw a straight line and spread with a wire bar(#10) to evenly coat the art paper. The gloss after drying (angle ofreflection: 75°) was measured with a Gloss Meter VG7000 (produced byNippon Denshoku Industries Co., Ltd.) and evaluated based on thestandard below. The flatness and the gloss of the coating film improveas the magenta pigment is dispersed more finely.

The gloss improvement rates for the magenta pigment dispersions (DIS1)to (DIS79) and (DIS87) that used a magenta pigment represented byformula (52) as a colorant were determined on the basis of the glossvalue of the magenta pigment dispersion (DIS83) for standard.

The gloss improvement rates for the magenta pigment dispersions (DIS80)and (DIS88) that used a magenta pigment represented by formula (53) as acolorant were determined on the basis of the gloss value of the magentapigment dispersion (DIS84) for standard.

The gloss improvement rates for the magenta pigment dispersions (DIS81)and (DIS89) that used a magenta pigment represented by formula (54) as acolorant were determined on the basis of the gloss value of the magentapigment dispersion (DIS85) for standard.

The gloss improvement rates for the magenta pigment dispersions (DIS82)and (DIS90) that used a magenta pigment represented by formula (55) as acolorant were determined on the basis of the gloss value of the magentapigment dispersion (DIS86) for standard.

The evaluation standard for the pigment dispersions is as follows.

A: The gloss value improvement rate was 30% or more.B: The gloss value improvement rate was 20% or more but less than 30%.C: The gloss value improvement rate was 10% or more but less than 20%.D: The gloss value improvement rate was less than 10%.

The magenta pigment dispersibility was evaluated as satisfactory as longas the gloss rate improvement rate was 10% or more.

The evaluation results for the magenta pigment dispersions are shown inTable 3.

TABLE 3 Magenta Gloss pigment Magenta (gloss dispersion Compound pigmentvalue) DIS1 101 Formula(52) A(70) DIS2 102 Formula(52) A(72) DIS3 103Formula(52) A(74) DIS4 104 Formula(52) A(73) DIS5 105 Formula(52) A(69)DIS6 106 Formula(52) A(75) DIS7 107 Formula(52) A(74) DIS8 108Formula(52) A(76) DIS9 109 Formula(52) A(71) DIS10 110 Formula(52) A(71)DIS11 111 Formula(52) A(70) DIS12 112 Formula(52) A(73) DIS13 113Formula(52) A(74) DIS14 114 Formula(52) A(75) DIS15 115 Formula(52)A(70) DIS16 116 Formula(52) A(76) DIS17 117 Formula(52) A(71) DIS18 118Formula(52) A(70) DIS19 119 Formula(52) A(75) DIS20 120 Formula(52)A(71) DIS21 121 Formula(52) A(70) DIS22 122 Formula(52) A(74) DIS23 123Formula(52) A(73) DIS24 124 Formula(52) A(75) DIS25 125 Formula(52)A(72) DIS26 126 Formula(52) A(76) DIS27 127 Formula(52) A(70) DIS28 128Formula(52) A(75) DIS29 129 Formula(52) A(74) DIS30 130 Formula(52)A(65) DIS31 131 Formula(52) A(73) DIS32 132 Formula(52) A(70) DIS33 133Formula(52) A(70) DIS34 134 Formula(52) A(72) DIS35 135 Formula(52)A(72) DIS36 136 Formula(52) A(74) DIS37 137 Formula(52) A(71) DIS38 138Formula(52) A(73) DIS39 139 Formula(52) A(69) DIS40 140 Formula(52)A(75) DIS41 141 Formula(52) A(67) DIS42 142 Formula(52) A(64) DIS43 143Formula(52) A(66) DIS44 144 Formula(52) A(64) DIS45 145 Formula(52)A(70) DIS46 146 Formula(52) A(72) DIS47 147 Formula(52) A(66) DIS48 148Formula(52) A(65) DIS49 149 Formula(52) A(77) DIS50 150 Formula(52)A(71) DIS51 151 Formula(52) A(70) DIS52 152 Formula(52) A(65) DIS53 153Formula(52) A(65) DIS54 154 Formula(52) A(64) DIS55 155 Formula(52)A(67) DIS56 156 Formula(52) A(66) DIS57 157 Formula(52) A(78) DIS58 158Formula(52) A(72) DIS59 159 Formula(52) A(77) DIS60 160 Formula(52)A(76) DIS61 161 Formula(52) A(64) DIS62 162 Formula(52) A(70) DIS63 163Formula(52) A(65) DIS64 164 Formula(52) A(77) DIS65 165 Formula(52)A(71) DIS66 166 Formula(52) A(73) DIS67 167 Formula(52) A(74) DIS68 168Formula(52) A(70) DIS69 169 Formula(52) A(72) DIS70 170 Formula(52)A(73) DIS71 171 Formula(52) A(73) DIS72 172 Formula(52) A(77) DIS73 173Formula(52) A(72) DIS74 174 Formula(52) A(65) DIS75 175 Formula(52)A(67) DIS76 176 Formula(52) A(66) DIS77 177 Formula(52) A(68) DIS78 178Formula(52) A(64) DIS79 179 Formula(52) B(67) DIS80 101 Formula(53)A(69) DIS81 101 Formula(54) A(80) DIS82 101 Formula(55) A(75) DIS83 NoneFormula(52) Standard(42) DIS84 None Formula(53) Standard(45) DIS85 NoneFormula(54) Standard(42) DIS86 None Formula(55) Standard(39) DIS87Comparative Formula(52) B(54) compound 1 DIS88 Comparative Formula(53)B(55) compound 1 DIS89 Comparative Formula(54) C(48) compound 1 DIS90Comparative Formula(55) B(50) compound 1

Example 4

A toner of the present invention was produced by the followingsuspension polymerization method.

Toner Production Example 1

To a 2 L four neck flask equipped with a high speed stirrer T.K.Homomixer (produced by PRIMIX Corporation), 710 parts of ion exchangewater and 450 parts of a 0.1 mol/l aqueous Na₃PO₄ solution were added.The speed of rotation was adjusted to 12000 rpm and the mixture washeated to 60° C. Thereto, 68 parts of a 1.0 mol/l aqueous CaCl₂ solutionwas slowly added to prepare a water-based medium containing finesparingly water-soluble dispersion stabilizer Ca₃(PO₄)₂. Then thecomposition below was heated to 60° C. and evenly dissolved anddispersed in a high sped stirrer T.K. Homomixer (produced by PRIMIXCorporation) at 5000 rpm.

magenta pigment dispersion (DIS1) 132 parts styrene monomer 46 partsn-butyl acrylate monomer 34 parts polar resin [saturated polyester resin(terephthalic acid- 10 parts propylene oxide-modified bisphenol A, acidvalue: 15, peak molecular weight: 6000)] ester wax (maximum endothermicpeak in DSC = 70° 25 parts C., Mn = 704) aluminum salicylate compound[produced by Orient 2 parts Chemical Industries Co., Ltd., trade name:BONTRON E-108] divinylbenzene monomer 0.1 parts

To this composition, 10 parts of 2,2′-azobis(2,4-dimethylvaleronitrile)serving as a polymerization initiator was added and the resultingmixture was placed in the water-based medium and formed into particleswhile retaining a rotation speed of 12000 rpm for 15 minutes. Then thehigh speed stirrer was changed to an impeller stirrer equipped with astirring blade, the polymerization was continued at a liquid temperatureof 60° C. for 5 hours, and then the liquid temperature was increased to80° C. The polymerization was continued for 8 hours. After terminationof the polymerization, the remaining monomers were distilled away at areduced pressure at 80° C. and the reaction product was cooled to 30° C.As a result, a polymer fine particle dispersion was obtained.

The polymer fine particle dispersion obtained was placed in a washingcontainer. Thereto, diluted hydrochloric acid was added under stirring.Stirring was conducted for 2 hours at pH of 1.5, a compound of calciumand a phosphoric acid containing Ca₃(PO₄)₂ was dissolved in thedispersion, and the resulting mixture was filtered to conduct solidliquid separation. As a result, polymer fine particles were obtained.The polymer fine particles were again placed in water to again form adispersion. Then the dispersion was separated into solid and liquidthrough a filter. This re-dispersing of the polymer fine particles inwater and solid liquid separation were repeated until the compound ofphosphoric acid and calcium containing Ca₃(PO₄)₂ was satisfactorilyremoved. Then polymer fine particles after final solid liquid separationwere thoroughly dried with a drier to obtain toner particles.

In a Henschel mixer, (produced by Nippon Coke & Engineering Co., Ltd.),100 parts of the toner particles obtained, 1.0 parts of hydrophobicsilica fine powder surface-treated with hexamethyldisilazane(number-average particle size of primary particles: 7 nm), 0.15 parts ofrutile-type titanium oxide fine powder (number-average particle size ofprimary particles: 45 nm), and 0.5 parts of a rutile-type titanium oxidefine powder (number-average particle size of primary particles: 200 nm)were dry-mixed for 5 minutes. As a result, a toner (TNR1) was obtained.

Toner Production Example 2

Toners (TNR2) to (TNR79) of the present invention were obtained as inToner Production Example 1 except that the magenta pigment dispersion(DIS1) in Toner Production Example 1 was changed to magenta pigmentdispersions (DIS2) to (DIS79).

Toner Production Example 3

Toners (TNR80) to (TNR82) of the present invention were obtained as inToner Production Example 1 except that the magenta pigment dispersion(DIS1) in Toner Production Example 1 was changed to magenta pigmentdispersions (DIS80) to (DIS82).

Comparative Example 2

A toner used as the standard for evaluation and a toner for comparisonfor the toners of the present invention produced in Example 4 wereproduced by the following method.

Production Example 1 of Toner for Standard

A toner (TNR83) for standard was obtained as in Toner Production Example1 except that the magenta pigment dispersion (DIS1) in Toner ProductionExample 1 was changed to magenta pigment dispersion (DIS83).

Production Example 2 of Toner for Standard

Toners (TNR84) to (TNR86) for standard were obtained as in TonerProduction Example 1 except that the magenta pigment dispersion (DIS1)in Toner Production Example 1 was changed to magenta pigment dispersions(DIS84) to (DIS86).

Production Example 1 of Toner for Comparison

A toner (TNR87) for comparison was obtained as in Toner ProductionExample 1 except that the magenta pigment dispersion (DIS1) in TonerProduction Example 1 was changed to magenta pigment dispersion (DIS87).

Production Example 2 of Toner for Comparison

Toners (TNR88) to (TNR90) for comparison were obtained as in TonerProduction Example 1 except that the magenta pigment dispersion (DIS1)in Toner Production Example 1 was changed to magenta pigment dispersions(DIS88) to (DIS90).

Example 5

A toner of the present invention was produced by the followingsuspension granulation method.

Toner Production Example 4

Mixed were 180 parts of ethyl acetate, 30 parts of Pigment Red 122, 3.0parts of the compound (101) having a azo skeleton structure, and 130parts of glass beads (1 mm in diameter). The resulting mixture wasdispersed in an attritor (produced by Nippon Coke & Engineering Co.,Ltd.) for 3 hours and filtered through a mesh to obtain a magentapigment dispersion.

The composition below was dispersed in a ball mill for 24 hours toobtain 200 parts of a toner composition mixed liquid.

magenta pigment dispersion 96.0 parts polar resin [saturated polyesterresin (a polycondensate of 85.0 parts propylene oxide-modified bisphenolA and phthalic acid, Tg = 75.9° C., Mw = 11000, Mn = 4200, acid value:11)] hydrocarbon wax (Fischer-Tropsch wax, maximum 9.0 parts endothermicpeak in DSC: = 80° C., Mw = 750) aluminum salicylate compound [BONTRONE-108 2.0 parts produced by Orient Chemical Industries Co., Ltd.] ethylacetate (solvent) 10.0 parts

The following composition was dispersed in a ball mill for 24 hours todissolve carboxy methyl cellulose and obtain a water-based medium.

calcium carbonate (coated with acrylic acid-based 20.0 parts copolymer)carboxy methyl cellulose [CELLOGEN BS-H, produced 0.5 parts by DaiichiKogyo Seiyaku Co., Ltd.] ion exchange water 99.5 parts

In a high speed stirrer T.K. Homomixer (produced by PRIMIX Corporation),1200 parts of the water-based medium was placed and 1000 parts of thetoner composition mixed liquid was added thereto while stirring thecontent with a rotating blade at a peripheral velocity of 20 m/sec.Stirring was conducted for 1 minute while retaining 25° C. so as toobtain a suspension.

While stirring 2200 parts of the suspension with FULLZONE impeller(produced by KOBELCO ECO-SOLUTIONS Co., Ltd.) at a peripheral velocityof 45 m/min, the liquid temperature was retained constant at 40° C. andthe gas phase on the suspension surface was forcibly suctioned through ablower to start removing the solvent. Fifteen minutes after start ofsolvent removal, 75 parts of ammonia water diluted to 1% as an ionicsubstance was added; 1 hour after start of solvent removal, 25 parts ofthe ammonia water was added; 2 hours after start of solvent removal, 25parts of the ammonia water was added; and lastly 3 hours after start ofsolvent removal, 25 parts of the ammonia water was added so that thetotal amount of the ammonia water added was 150 parts. The liquidtemperature was retained at 40° C. for 17 hours after start of thesolvent removal. As a result, a toner dispersion obtained by removingthe solvent (ethyl acetate) from the suspended particles was obtained.

To 300 parts of the toner dispersion obtained by the solvent removalstep, 80 parts of 10 mol/l hydrochloric acid was added. The resultingmixture was neutralized with a 0.1 mol/l aqueous sodium hydroxidesolution and washed four times with ion exchange water by suctionfiltration to obtain a toner cake. The toner cake was dried in a vacuumdrier and passed through a 45 μm sieve to obtain toner particles. Thesubsequent operation was the same as Toner Production Example 1 and atoner (TNR91) was obtained.

Toner Production Example 5

Toners (TNR92) to (TNR169) of the present invention were obtained as inToner Production Example 4 except that the compound (101) having an azoskeleton structure was changed to compounds (102) to (179).

Toner Production Example 6

Toners (TNR170) to (TNR172) of the present invention were obtained as inToner Production Example 5 except that the magenta pigment representedby formula (52) was changed to those represented by formulae (53) to(55).

Comparative Example 3

A toner used as the standard for evaluation and a toner for comparisonfor the toners of the present invention produced in Example 5 wereproduced by the following method.

Production Example 3 of Toner for Standard

A toner (TNR173) for standard was obtained as in Toner ProductionExample 4 except that the compound (101) having an azo skeletonstructure was not added.

Production Example 4 of Toner for Standard

Toners (TNR174) to (TNR176) for standard were obtained as in TonerProduction Example 6 except that the compound (101) having an azoskeleton structure was not added.

Production Example 3 of Toner for Comparison

A toner (TNR177) for comparison was obtained as in Toner ProductionExample 4 except that the compound (101) having an azo skeletonstructure was changed to DA-703-50 (product of produced by KusumotoChemicals Ltd.) described in Japanese Patent Laid-Open No. 2006-30760.

Production Example 4 of Toner for Comparison

Toners (TNR178) to (TNR180) for comparison were obtained as inProduction Example 3 of toner for comparison except that the magentapigment represented by formula (52) in Production Example 3 of toner forcomparison was changed to those represented by formulae (53) to (55).

Example 6

Toners obtained in the present invention were evaluated by the followingmethod.

The toners (TNR1) to (TNR90) and (TNR91) to (TNR180) were used to outputimage samples and the image properties described below were compared andevaluated. In comparing the image properties, a modified model ofLBP-5300 (produced by Canon Kabushiki Kaisha) was used as an imageforming apparatus (hereinafter referred to as LBP) to feed paper. Theapparatus was modified by changing a development blade in a processcartridge (referred to as CRG hereinafter) to a SUS blade having athickness of 8 μm. The apparatus was also modified to apply a blade biasof −200 V relative to development bias applied to a development roller,which served as a toner bearing member.

Measurement of Weight-Average Particle Size D4 and Number-AverageParticle Size D1 of Toner

Coulter Multisizer (produced by Beckman Coulter Inc.) was used and aninterface (produced by Nikkaki Bios Co., Ltd.) for outputting numberdistribution and volume distribution and a personal computer wereconnected thereto. The electrolyte used was a 1% aqueous NaCl solutionusing sodium chloride. For example, ISOTON R-II (produced by BeckmanCoulter Inc.) can be used. A specific measurement procedure is describedin catalog (February 2002 version) of Coulter Multisizer published byCoulter and operation manuals for analyzers. For example, the proceduremay be as follows.

To 100 to 150 ml of the aqueous electrolyte solution, 2 to 20 mg of ameasurement sample was added. The electrolyte in which the sample wassuspended was dispersed with an ultrasonic disperser for about 1 to 3minutes and the volume and number of the toner particles 2.0 μm or moreand 64.0 μm or less in size were measured by using 100 μm apertures ofCoulter Multisizer. The obtained data was distributed into 16 channelsto determine the weight-average particle size D4, the number-averageparticle size D1, and the D4/D1 ratio.

Evaluation of Coloring Power of Toner

In a normal temperature, normal humidity (N/N (23.5° C., 60% RH))environment, a solid image with a toner amount of 0.5 mg/cm² on atransfer paper (75 g/m² paper) was formed. A reflection densitometerSpectrolino (produced by GretagMacbeth) was used to measure the densityof the solid image. The coloring power of the toner was evaluated on thebasis of the solid image density improvement rate.

The solid image density improvement rate for the toners (TNR1) to(TNR82) was determined on the basis of the solid image density for thetoners (TNR83) to (TNR86) for evaluation.

The solid image density improvement rate for the toners (TNR90) to(TNR172) was determined on the basis of the solid image density for thetoners (TNR173) to (TNR176) for evaluation.

The evaluation standard of the solid image density improvement rate isas follows.

A: The solid image density improvement rate was 20% or more.B: The solid image density improvement rate was 10% or more but lessthan 20%.C: The solid image density improvement rate was 5% or more but less than10%.D: The solid image density improvement rate was less than 5%.

The coloring power was considered satisfactory as long as the solidimage density improvement rate was 5% or more.

The results of coloring power evaluation of the toners prepared bysuspension polymerization are shown in Tables 4-1 and 4-2 and theresults of coloring power evaluation of the toners prepared bysuspension granulation are shown in Tables 5-1 and 5-2.

Evaluation of Toner Fogging

In a normal temperature, normal humidity (N/N (23.5° C., 60% RH))environment and in a high-temperature, high-humidity (H/H (30° C., 80%RH)) environment, an image output test of making 10,000 printouts of animage having a printing ratio of 2% was conducted on transfer paper (75g/m² paper). At the end of the test, an image having a white backgroundportion was output. The whiteness (reflectance Ds (%)) of the whitebackground portion of the printout image was measured with REFLECTMETERMODEL TC-6DS (produced by Nippon Denshoku Industries Co., Ltd.) and thedifference between this whiteness and the whiteness (average reflectanceDr (%)) of the transfer paper was determined [=Dr (%)−Ds (%)] andassumed to be the fogging density (%). The fogging at the end of thetest was evaluated.

A: Less than 1.0%B: 1.0% or more but less than 2.0%C: 2.0% or more but less than 3.0%D: 3.0% or more

The fogging density was evaluated as practically acceptable as long asthe fogging density was less than 3%.

The evaluation results concerning fogging of the toners produced bysuspension polymerization are shown in Tables 4-1 and 4-2 and theevaluation results concerning fogging of the toners produced bysuspension granulation are shown in Tables 5-1 and 5-2.

Evaluation of Toner Transfer Efficiency

In a high-temperature, high-humidity (H/H (30° C., 80% RH)) environment,an image output test of making 10,000 printouts of an image having aprinting ratio of 2% was conducted on transfer paper (75 g/m² paper). Atthe end of the test, the transfer efficiency was confirmed. A solidimage having a toner amount of 0.65 mg/cm² was developed on a drum andthen transferred to a sheet of transfer paper (75 g/m² paper) to obtainan unfixed image. The transfer efficiency was determined on the basis ofthe difference in mass between the amount of the toner on the drum andthe amount of the toner on the transfer paper. The transfer efficiencywas assumed to be 100% when all of the toner on the drum was transferredonto the transfer paper. The evaluation standard for the transferefficiency was as follows.

A: The transfer efficiency was 95% or more.B: The transfer efficiency was 90% or more but less than 95%.C: The transfer efficiency was 80% or more but less than 90%.D: The transfer efficiency was less than 80%.

The transfer efficiency was considered satisfactory if the transferefficiency was 80% or more.

The evaluation results of transfer efficiency of the toners produced bysuspension polymerization are shown in Tables 4-1 and 4-2 and theevaluation results of transfer efficiency of the toners produced bysuspension granulation are shown in Tables 5-1 and 5-2.

Comparative Example 5

The coloring power, fogging, and transfer efficiency of the toners(TNR87) to (TNR90), (TNR177) to (TNR180) for comparison were evaluatedas in Example 6.

The solid image density improvement rate of the toners (TNR87) to(TNR90) for comparison was evaluated on the basis of the solid imagedensity of the toners (TNR83) to (TNR86) for standard.

The solid image density improvement rate of the toners (TNR177) to(TNR180) for comparison was evaluated on the basis of the solid imagedensity of the toners (TNR173) to (TNR176) for standard.

The evaluation results for the toners for comparison prepared bysuspension polymerization are shown in Tables 4-1 and 4-2 and theevaluation results for the toners for comparison prepared by suspensiongranulation are shown in Tables 5-1 and 5-2.

TABLE 4-1 Toner particles Pigment Magenta D4 Coloring Fogging FoggingTransfer Toner dispersion Compound pigment [μm] D4/D1 power [N/N] [H/H]property TNR1 DIS1 101 Formula(52) 6.30 1.17 A A A A TNR2 DIS2 102Formula(52) 6.27 1.13 A A A A TNR3 DIS3 103 Formula(52) 6.19 1.19 A A AA TNR4 DIS4 104 Formula(52) 6.27 1.16 A A A A TNR5 DIS5 105 Formula(52)6.15 1.20 A A A A TNR6 DIS6 106 Formula(52) 6.32 1.23 A A A A TNR7 DIS7107 Formula(52) 6.28 1.19 A A A A TNR8 DIS8 108 Formula(52) 6.42 1.22 AA A A TNR9 DIS9 109 Formula(52) 6.29 1.22 A A A A TNR10 DIS10 110Formula(52) 6.32 1.18 A A A A TNR11 DIS11 111 Formula(52) 6.23 1.21 A AA A TNR12 DIS12 112 Formula(52) 6.21 1.20 A A A A TNR13 DIS13 113Formula(52) 6.09 1.18 A A A A TNR14 DIS14 114 Formula(52) 6.14 1.20 A AA A TNR15 DIS15 115 Formula(52) 6.36 1.18 A A A A TNR16 DIS16 116Formula(52) 6.11 1.22 A A A A TNR17 DIS17 117 Formula(52) 6.35 1.20 A AA A TNR18 DIS18 118 Formula(52) 6.28 1.17 A A A A TNR19 DIS19 119Formula(52) 6.06 1.15 A A A A TNR20 DIS20 120 Formula(52) 6.13 1.15 A AA A TNR21 DIS21 121 Formula(52) 6.25 1.18 A A A A TNR22 DIS22 122Formula(52) 6.04 1.20 A A A A TNR23 DIS23 123 Formula(52) 6.12 1.16 A AA A TNR24 DIS24 124 Formula(52) 6.19 1.18 A A A A TNR25 DIS25 125Formula(52) 6.13 1.15 A A A A TNR26 DIS26 126 Formula(52) 6.08 1.19 A AA A TNR27 DIS27 127 Formula(52) 6.05 1.14 A A A A TNR28 DIS28 128Formula(52) 6.38 1.21 A A A A TNR29 DIS29 129 Formula(52) 6.10 1.23 A AA A TNR30 DIS30 130 Formula(52) 6.44 1.28 B B B B TNR31 DIS31 131Formula(52) 6.24 1.12 A A A A TNR32 DIS32 132 Formula(52) 6.09 1.15 A AA A TNR33 DIS33 133 Formula(52) 6.36 1.21 A A A A TNR34 DIS34 134Formula(52) 6.32 1.15 A A A A TNR35 DIS35 135 Formula(52) 6.16 1.18 A AA A TNR36 DIS36 136 Formula(52) 6.09 1.23 A A A A TNR37 DIS37 137Formula(52) 6.17 1.20 A A A A TNR38 DIS38 138 Formula(52) 6.26 1.18 A AA A TNR39 DIS39 139 Formula(52) 6.16 1.12 A A A A TNR40 DIS40 140Formula(52) 6.27 1.20 A A A A TNR41 DIS41 141 Formula(52) 6.42 1.26 B BB B TNR42 DIS42 142 Formula(52) 6.39 1.29 B B B B TNR43 DIS43 143Formula(52) 6.62 1.24 B B B B TNR44 DIS44 144 Formula(52) 6.36 1.25 B BB B TNR45 DIS45 145 Formula(52) 6.26 1.21 A A A A

TABLE 4-2 Toner particles Pigment Magenta D4 Coloring Fogging FoggingTransfer Toner dispersion Compound pigment [μm] D4/D1 power [N/N] [H/H]property TNR46 DIS46 146 Formula(52) 6.29 1.19 A A A A TNR47 DIS47 147Formula(52) 6.33 1.17 B B B B TNR48 DIS48 148 Formula(52) 6.19 1.18 B BB B TNR49 DIS49 149 Formula(52) 6.27 1.20 A A A A TNR50 DIS50 150Formula(52) 6.22 1.15 A A A A TNR51 DIS51 151 Formula(52) 6.35 1.18 A AA A TNR52 DIS52 152 Formula(52) 6.22 1.32 B B B B TNR53 DIS53 153Formula(52) 6.38 1.25 B B B B TNR54 DIS54 154 Formula(52) 6.20 1.23 B BB B TNR55 DIS55 155 Formula(52) 6.48 1.30 B B B B TNR56 DIS56 156Formula(52) 6.27 1.29 B B B B TNR57 DIS57 157 Formula(52) 6.17 1.18 A AA A TNR58 DIS58 158 Formula(52) 6.08 1.21 A A A A TNR59 DIS59 159Formula(52) 6.21 1.16 A A A A TNR60 DIS60 160 Formula(52) 6.47 1.23 A AA A TNR61 DIS61 161 Formula(52) 6.48 1.30 B B B B TNR62 DIS62 162Formula(52) 6.21 1.17 A A A A TNR63 DIS63 163 Formula(52) 6.39 1.31 B BB B TNR64 DIS64 164 Formula(52) 6.18 1.15 A A A A TNR65 DIS65 165Formula(52) 6.28 1.19 A A A A TNR66 DIS66 166 Formula(52) 6.26 1.15 A AA A TNR67 DIS67 167 Formula(52) 6.17 1.24 A A A A TNR68 DIS68 168Formula(52) 6.30 1.18 A A A A TNR69 DIS69 169 Formula(52) 6.26 1.22 A AA A TNR70 DIS70 170 Formula(52) 6.31 1.26 A A A A TNR71 DIS71 171Formula(52) 6.27 1.19 A A A A TNR72 DIS72 172 Formula(52) 6.13 1.21 A AA A TNR73 DIS73 173 Formula(52) 6.30 1.25 A A A A TNR74 DIS74 174Formula(52) 6.40 1.29 B B B B TNR75 DIS75 175 Formula(52) 6.37 1.23 B BB B TNR76 DIS76 176 Formula(52) 6.44 1.25 B B B B TNR77 DIS77 177Formula(52) 6.11 1.28 B B B B TNR78 DIS78 178 Formula(52) 6.30 1.22 B BB B TNR79 DIS79 179 Formula(52) 6.14 1.28 B B B B TNR80 DIS80 101Formula(53) 6.06 1.18 A A A A TNR81 DIS81 101 Formula(54) 6.25 1.22 A AA A TNR82 DIS82 101 Formula(55) 6.11 1.18 A A A A TNR83 DIS83 NoneFormula(52) 6.82 1.32 D D D D TNR84 DIS84 None Formula(53) 6.51 1.25 D DD D TNR85 DIS85 None Formula(54) 6.68 1.29 D D D D TNR86 DIS86 NoneFormula(55) 6.60 1.23 D D D D TNR87 DIS87 Comparative Formula(52) 7.251.38 D D D D compound 1 TNR88 DIS88 Comparative Formula(53) 6.92 1.33 DD D D compound 1 TNR89 DIS89 Comparative Formula(54) 7.01 1.31 D D D Dcompound 2 TNR90 DIS90 Comparative Formula(55) 6.73 1.34 D D D Dcompound 3

TABLE 5-1 Toner particles Magenta D4 Coloring Fogging Fogging TransferToner Compound pigment [μm] D4/D1 power [N/N] [H/H] property TNR91 101Formula(52) 6.19 1.21 A A A A TNR92 102 Formula(52) 6.34 1.24 A A A ATNR93 103 Formula(52) 6.30 1.17 A A A A TNR94 104 Formula(52) 6.27 1.20A A A A TNR95 105 Formula(52) 6.13 1.22 A A A A TNR96 106 Formula(52)6.31 1.21 A A A A TNR97 107 Formula(52) 6.39 1.19 A A A A TNR98 108Formula(52) 6.32 1.20 A A A A TNR99 109 Formula(52) 6.38 1.21 A A A ATNR100 110 Formula(52) 6.22 1.19 A A A A TNR101 111 Formula(52) 6.271.20 A A A A TNR102 112 Formula(52) 6.20 1.19 A A A A TNR103 113Formula(52) 6.13 1.18 A A A A TNR104 114 Formula(52) 6.08 1.22 A A A ATNR105 115 Formula(52) 6.19 1.24 A A A A TNR106 116 Formula(52) 6.161.18 A A A A TNR107 117 Formula(52) 6.25 1.17 A A A A TNR108 118Formula(52) 6.22 1.24 A A A A TNR109 119 Formula(52) 6.14 1.21 A A A ATNR110 120 Formula(52) 6.33 1.18 A A A A TNR111 121 Formula(52) 6.211.19 A A A A TNR112 122 Formula(52) 6.11 1.17 A A A A TNR113 123Formula(52) 6.13 1.15 A A A A TNR114 124 Formula(52) 6.08 1.16 A A A ATNR115 125 Formula(52) 6.04 1.19 A A A A TNR116 126 Formula(52) 6.021.17 A A A A TNR117 127 Formula(52) 6.08 1.15 A A A A TNR118 128Formula(52) 6.36 1.24 A A A A TNR119 129 Formula(52) 6.19 1.22 A A A ATNR120 130 Formula(52) 6.24 1.32 B B B B TNR121 131 Formula(52) 6.331.27 A A A A TNR122 132 Formula(52) 6.07 1.21 A A A A TNR123 133Formula(52) 6.30 1.20 A A A A TNR124 134 Formula(52) 6.24 1.24 A A A ATNR125 135 Formula(52) 6.19 1.26 A A A A TNR126 136 Formula(52) 6.261.19 A A A A TNR127 137 Formula(52) 6.28 1.26 A A A A TNR128 138Formula(52) 6.11 1.19 A A A A TNR129 139 Formula(52) 6.23 1.23 A A A ATNR130 140 Formula(52) 6.30 1.24 A A A A TNR131 141 Formula(52) 6.251.29 B B B B TNR132 142 Formula(52) 6.49 1.30 B B B B TNR133 143Formula(52) 6.52 1.31 B B B B TNR134 144 Formula(52) 6.32 1.33 B B B BTNR135 145 Formula(52) 6.33 1.21 A A A A

TABLE 5-2 Toner particles Magenta D4 Coloring Fogging Fogging TransferToner Compound pigment [μm] D4/D1 power [N/N] [H/H] property TNR136 146Formula(52) 6.35 1.21 A A A A TNR137 147 Formula(52) 6.47 1.28 B B B BTNR138 148 Formula(52) 6.39 1.30 B B B B TNR139 149 Formula(52) 6.091.18 A A A A TNR140 150 Formula(52) 6.39 1.22 A A A A TNR141 151Formula(52) 6.31 1.24 A A A A TNR142 152 Formula(52) 6.13 1.33 B B B BTNR143 153 Formula(52) 6.27 1.30 B B B B TNR144 154 Formula(52) 6.221.28 B B B B TNR145 155 Formula(52) 6.38 1.27 B B B B TNR146 156Formula(52) 6.43 1.30 B B B B TNR147 157 Formula(52) 6.32 1.16 A A A ATNR148 158 Formula(52) 6.14 1.21 A A A A TNR149 159 Formula(52) 6.231.28 A A A A TNR150 160 Formula(52) 6.36 1.19 A A A A TNR151 161Formula(52) 6.31 1.32 B B B B TNR152 162 Formula(52) 6.30 1.27 A A A ATNR153 163 Formula(52) 6.24 1.29 B B B B TNR154 164 Formula(52) 6.261.26 A A A A TNR155 165 Formula(52) 6.25 1.25 A A A A TNR156 166Formula(52) 6.32 1.21 A A A A TNR157 167 Formula(52) 6.11 1.25 A A A ATNR158 168 Formula(52) 6.32 1.26 A A A A TNR159 169 Formula(52) 6.321.28 A A A A TNR160 170 Formula(52) 6.14 1.19 A A A A TNR161 171Formula(52) 6.22 1.26 A A A A TNR162 172 Formula(52) 6.17 1.22 A A A ATNR163 173 Formula(52) 6.14 1.19 A A A A TNR164 174 Formula(52) 6.301.25 B B B B TNR165 175 Formula(52) 6.29 1.31 B B B B TNR166 176Formula(52) 6.41 1.30 B B B B TNR167 177 Formula(52) 6.37 1.32 B B B BTNR168 178 Formula(52) 6.44 1.31 B B B B TNR169 179 Formula(52) 6.581.32 B B B B TNR170 101 Formula(53) 6.12 1.23 A A A A TNR171 101Formula(54) 6.28 1.29 A A A A TNR172 101 Formula(55) 6.11 1.18 A A A ATNR173 None Formula(52) 6.69 1.35 D D D D TNR174 None Formula(53) 6.531.33 D D D D TNR175 None Formula(54) 6.48 1.30 D D D D TNR176 NoneFormula(55) 6.42 1.27 D D D D TNR177 Comparative Formula(52) 6.38 1.29 DD D D compound 1 TNR178 Comparative Formula(53) 6.40 1.27 D D D Dcompound 1 TNR179 Comparative Formula(54) 6.59 1.34 D D D D compound 1TNR180 Comparative Formula(55) 6.61 1.30 D D D D compound 1

Table 3 clearly shows that the dispersibility of the magenta pigmentinto the binder resin is improved by using a compound having an azoskeleton structure.

Tables 4-1 and 4-2 clearly show that use of a compound having an azoskeleton structure improves dispersibility of the magenta pigment intothe binder resin and thus a magenta toner with satisfactory coloringpower is provided. Use of a compound having an azo skeleton structurealso suppresses fogging and a magenta toner that has high transferefficiency is provided. Tables 5-1 and 5-2 clearly show that even whensuspension granulation is employed, the dispersibility of the magentapigment into the binder resin is improved, fogging is suppressed, and atoner having satisfactory coloring power as well as high transferefficiency is provided.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2012-043073 filed Feb. 29, 2012, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A magenta toner comprising toner particles, eachof which contains a binder resin; a compound and a magenta pigment thecompound has a structure, a polymer portion of which has a monomer unitrepresented by formula (2) and is bound to a structure represented byformula (5);

where, in formula (5), each R₁ independently represents a hydrogen atom,a halogen atom, an alkyl group, an alkoxy group, a trifluoromethylgroup, a cyano group, or a hydroxyl group; R₉ and R₁₀ each independentlyrepresent an alkyl group, a phenyl group, an OR₄ group, or an NR₅R₆group; R₄ to R₆ independently represent a hydrogen atom, an alkyl group,a phenyl group, or an aralkyl group; R₂₆ to R₃₀ independently representa hydrogen atom, a COOR₂₁ group, a CONR₂₂R₂₃ group, a NHCOR₂₄ group, oran OR₂₅ group; R₂₁ to R₂₅ independently represent a hydrogen atom, analkyl group, an aryl group, or an aralkyl group; l represents 4; and Lrepresents a divalent linking group that binds to the polymer portion,

where, in formula (2), R₇ represents a hydrogen atom or an alkyl group;and R₈ represents a phenyl group, a carboxyl group, a carboxylic acidester group, or a carboxylic acid amide group.
 2. The magenta toneraccording to claim 1, where at least one of R₂₆ to R₃₀ in formula (5)represents a COOR₂₁ group or a CONR₂₂R₂₃ group; R₂₁ to R₂₃ independentlyrepresent a hydrogen atom, an alkyl group, an aryl group, or an aralkylgroup; and R₁ represents a hydrogen atom.
 3. The magenta toner accordingto claim 1, wherein the structure represented by formula (5) is astructure represented by formula (7) below

where, in formula (7), each R₁ independently represents a hydrogen atom,a halogen atom, an alkyl group, an alkoxy group, a trifluoromethylgroup, a cyano group, or a hydroxyl group; each R₉ independentlyrepresents an alkyl group, a phenyl group, an OR₄ group, or an NR₅R₆group; R₄ to R₆ each independently represent a hydrogen atom, an alkylgroup, a phenyl group, or an aralkyl group; p represents an integer of 2or 3; q represents an integer of 3 or 4; p+q=6; and L represents adivalent linking group that binds to the polymer portion.
 4. The magentatoner according to claim 3, where R₁ in formula (7) represents ahydrogen atom and q represents 3 or
 4. 5. The magenta toner according toclaim 1, wherein the magenta pigment is a pigment represented by formula(8):

where, in formula (8), R₃₁ to R₃₈ independently represent a hydrogenatom, a chlorine atom, or a methyl group.
 6. The magenta toner accordingto claim 1, wherein the magenta pigment is a pigment represented byformula (9):

where, in formula (9), R₃₉ to R₄₄ independently represent a hydrogenatom, a chlorine atom, a tert-butyl group, a cyano group, or a phenylgroup.
 7. The magenta toner according to claim 1, wherein the tonerparticles are prepared by a suspension polymerization method or asuspension granulation method.